Alt-Svc allows the server to indicate to the web browser that a resource should be loaded on a different server. Because this is a persistent setting, it could be used to track users across websites if it is not correctly partitioned.

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, h3result, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, Error: Unsupportedresult, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, truepassed: true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: Error: Unsupportedresult, different first party: h2unsupported: truepassed: undefinedtest failed: false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, h3result, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, h3result, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, h3result, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, h3result, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, h3result, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party:Error: Unsupported,h3,Error: Unsupported,h3,Error: Unsupportedresult, different first party: h2, h2, h2, h2, h2unsupported: true, false, true, false, truepassed: , true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: Error: Unsupportedresult, different first party: h2unsupported: truepassed: undefinedtest failed: false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, h3result, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same first party: h3, h3, h3, h3, h3result, different first party: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

A 'blob URL' is a local reference to some raw data. Trackers can use a blob URL to share data between websites.

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party:Error: Failed to fetch,Error: Failed to fetch,Error: Failed to fetch,Error: Failed to fetch,Error: Failed to fetchunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: Error: Load failedunsupported: falsepassed: truetest failed: false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party:Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party:Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party:Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.,Error: NetworkError when attempting to fetch resource.unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party:Error: Load failed,Error: Load failed,Error: Load failed,Error: Load failed,Error: Load failedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party: Error: NetworkError when attempting to fetch resource.unsupported: falsepassed: truetest failed: false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party:Error: Failed to fetch,Error: Failed to fetch,Error: Failed to fetch,Error: Failed to fetch,Error: Failed to fetchunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let blobURL = URL.createObjectURL(new Blob([secret]));        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);      } catch (e) {        throw new Error("Unsupported");      }    }read: async (secret) => {      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);      let result = await response.json();      let blobUrl = decodeURIComponent(result.blobUrl);      let blobResponse = await fetch(blobUrl);      return blobResponse.text();    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

A BroadcastChannel is designed to send messages between tabs. In some browsers it can be used for cross-site communication and tracking.

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: Error: no BroadcastChannel messageunsupported: falsepassed: truetest failed: false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party:Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party: Error: The operation is insecure.unsupported: falsepassed: truetest failed: false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      try {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data === "request") {            bc.postMessage(secret);          }        };      } catch (e) {        throw new Error("Unsupported");      }    }read: () =>      new Promise((resolve, reject) => {        let bc = new BroadcastChannel("secrets");        bc.onmessage = (event) => {          if (event.data !== "request") {            resolve(event.data);          }        };        bc.postMessage("request");        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);      })result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party:Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel message,Error: no BroadcastChannel messageunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The Cache API is a content storage mechanism originally introduced to support ServiceWorkers. If the same Cache object is accessible to multiple websites, it can be abused to track users.

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party:Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party:Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url')unsupported: falsepassed: truetest failed: false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party:Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party:Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party:Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party:Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party:Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party:Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party: Error: The operation is insecure.unsupported: falsepassed: truetest failed: false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party:Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party:Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url'),Error: Cannot read properties of undefined (reading 'url')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f_http,dad47994-1478-4269-bc67-9d5be7279695_http,a224b08b-56ca-430a-8291-a1391ce3f527_http,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_http,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_httpresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_http,9e792e5f-2682-45df-a4b6-9926c1368572_http,96cb1992-e972-4aef-8062-ef9c5ed16a01_http,be33e986-4227-4dad-98ab-849158191238_http,d1bff213-a9f5-41c3-a065-c8b074cff472_httpresult, different first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_http,9e792e5f-2682-45df-a4b6-9926c1368572_http,96cb1992-e972-4aef-8062-ef9c5ed16a01_http,be33e986-4227-4dad-98ab-849158191238_http,d1bff213-a9f5-41c3-a065-c8b074cff472_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_httpresult, different first party: nullunsupported: falsepassed: truetest failed: false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f_http,b33c419d-acf6-4795-95e0-d5d753f2f16d_http,6a79070f-7300-4f0a-b3e4-67db8452282d_http,fc4e16e7-ac2e-48a9-8623-332158912d29_http,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_httpresult, different first party:026115d8-5ec8-4705-b68d-299ea05d729f_http,b33c419d-acf6-4795-95e0-d5d753f2f16d_http,6a79070f-7300-4f0a-b3e4-67db8452282d_http,fc4e16e7-ac2e-48a9-8623-332158912d29_http,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_http,3c6d0906-4d80-439c-9124-ff2647fc503f_http,29934d34-345f-4b44-91a5-4cfc4705276b_http,c261a896-1dbf-455d-8a32-c51b15883279_http,4befec68-5b8d-4639-b156-03db7501a173_httpresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:15e21312-33db-4994-b766-baad8032803f_http,7ccbfb90-229d-427c-9f22-79caffc2fec3_http,ab247bb9-7408-43c0-81f4-22f7335617f7_http,1cc5af75-9209-4c31-a70b-5f98374d6544_http,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_httpresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92_http,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56_http,f2c54d89-4429-43be-9044-840a1c275e7f_http,91894484-f7cc-4015-ae96-635239333863_http,d4713458-e4ff-458e-b8a8-0a3562d0441b_httpresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_http,299e3cd4-7953-4f77-801f-8985b822ac24_http,aad11fab-6660-48f9-b28d-4b2ee45a44df_http,d31fb840-54e6-4419-b2ca-f532e60327ac_http,8003e0ac-cbd3-4236-932f-a79792d54b62_httpresult, different first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_http,299e3cd4-7953-4f77-801f-8985b822ac24_http,aad11fab-6660-48f9-b28d-4b2ee45a44df_http,d31fb840-54e6-4419-b2ca-f532e60327ac_http,8003e0ac-cbd3-4236-932f-a79792d54b62_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_http,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_http,3ac91718-3eba-45e8-aceb-765d0391821b_http,f2d6741d-a215-4cac-a81a-dec44031672d_http,576d3332-f9c6-455d-bddd-b3b643b6c552_httpresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81_httpresult, different first party: nullunsupported: falsepassed: truetest failed: false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e_http,6d1c53c8-70cf-47eb-9a21-0ba706352479_http,5894b594-2a38-4d3a-be5d-e53e01ad93d1_http,e198d1f6-c1a6-4343-9907-302129e685e7_http,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_httpresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_http,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_http,32f534ec-f0c9-4fb9-a393-c743feebc30e_http,085080b8-ac7e-4d13-b00e-fceb219d3dac_http,e74254c5-9034-45cd-b7ba-b7db726e55ab_httpresult, different first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_http,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_http,32f534ec-f0c9-4fb9-a393-c743feebc30e_http,085080b8-ac7e-4d13-b00e-fceb219d3dac_http,e74254c5-9034-45cd-b7ba-b7db726e55ab_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f_js,dad47994-1478-4269-bc67-9d5be7279695_js,a224b08b-56ca-430a-8291-a1391ce3f527_js,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_js,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_jsresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_js,9e792e5f-2682-45df-a4b6-9926c1368572_js,96cb1992-e972-4aef-8062-ef9c5ed16a01_js,be33e986-4227-4dad-98ab-849158191238_js,d1bff213-a9f5-41c3-a065-c8b074cff472_jsresult, different first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_js,9e792e5f-2682-45df-a4b6-9926c1368572_js,96cb1992-e972-4aef-8062-ef9c5ed16a01_js,be33e986-4227-4dad-98ab-849158191238_js,d1bff213-a9f5-41c3-a065-c8b074cff472_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_jsresult, different first party: nullunsupported: falsepassed: truetest failed: false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:026115d8-5ec8-4705-b68d-299ea05d729f_js,b33c419d-acf6-4795-95e0-d5d753f2f16d_js,6a79070f-7300-4f0a-b3e4-67db8452282d_js,fc4e16e7-ac2e-48a9-8623-332158912d29_js,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_jsresult, different first party:026115d8-5ec8-4705-b68d-299ea05d729f_js,b33c419d-acf6-4795-95e0-d5d753f2f16d_js,6a79070f-7300-4f0a-b3e4-67db8452282d_js,fc4e16e7-ac2e-48a9-8623-332158912d29_js,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_js,3c6d0906-4d80-439c-9124-ff2647fc503f_js,29934d34-345f-4b44-91a5-4cfc4705276b_js,c261a896-1dbf-455d-8a32-c51b15883279_js,4befec68-5b8d-4639-b156-03db7501a173_jsresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:15e21312-33db-4994-b766-baad8032803f_js,7ccbfb90-229d-427c-9f22-79caffc2fec3_js,ab247bb9-7408-43c0-81f4-22f7335617f7_js,1cc5af75-9209-4c31-a70b-5f98374d6544_js,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_jsresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92_js,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56_js,f2c54d89-4429-43be-9044-840a1c275e7f_js,91894484-f7cc-4015-ae96-635239333863_js,d4713458-e4ff-458e-b8a8-0a3562d0441b_jsresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_js,299e3cd4-7953-4f77-801f-8985b822ac24_js,aad11fab-6660-48f9-b28d-4b2ee45a44df_js,d31fb840-54e6-4419-b2ca-f532e60327ac_js,8003e0ac-cbd3-4236-932f-a79792d54b62_jsresult, different first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_js,299e3cd4-7953-4f77-801f-8985b822ac24_js,aad11fab-6660-48f9-b28d-4b2ee45a44df_js,d31fb840-54e6-4419-b2ca-f532e60327ac_js,8003e0ac-cbd3-4236-932f-a79792d54b62_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_js,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_js,3ac91718-3eba-45e8-aceb-765d0391821b_js,f2d6741d-a215-4cac-a81a-dec44031672d_js,576d3332-f9c6-455d-bddd-b3b643b6c552_jsresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81_jsresult, different first party: nullunsupported: falsepassed: truetest failed: false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:24441439-f1db-4c84-bc96-50682c4e643e_js,6d1c53c8-70cf-47eb-9a21-0ba706352479_js,5894b594-2a38-4d3a-be5d-e53e01ad93d1_js,e198d1f6-c1a6-4343-9907-302129e685e7_js,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_jsresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_js,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_js,32f534ec-f0c9-4fb9-a393-c743feebc30e_js,085080b8-ac7e-4d13-b00e-fceb219d3dac_js,e74254c5-9034-45cd-b7ba-b7db726e55ab_jsresult, different first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_js,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_js,32f534ec-f0c9-4fb9-a393-c743feebc30e_js,085080b8-ac7e-4d13-b00e-fceb219d3dac_js,e74254c5-9034-45cd-b7ba-b7db726e55ab_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: Error: Type errorunsupported: falsepassed: truetest failed: false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedresult, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party:Error: Type error,Error: Type error,Error: Type error,Error: Type error,Error: Type errorunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party: Error: Unsupportedresult, different first party: Error: Unsupportedunsupported: truepassed: undefinedtest failed: false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_9779759484487227,fake_6435604947722651,fake_16629559953023265,fake_42172510931189033,fake_6114822711875867result, different first party:fake_1306126338742133,fake_7099112130713392,fake_08345205696376556,fake_16832344070277272,fake_1747713081783815unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_7997452452770248,fake_44263788403385695,fake_44133079893591054,fake_49401168311081234,fake_8093259252649003result, different first party:fake_29034223184068475,fake_43988095687258344,fake_35414824064754646,fake_4508179452959902,fake_21386841891247932unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party: fake_35745384229741695result, different first party: fake_09659913620784466unsupported: falsepassed: truetest failed: false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_32531483983461795,fake_38509268987081446,fake_4421695170451565,fake_5060872504553542,fake_14381124077105367result, different first party:fake_16357948975021186,fake_14347639572128923,fake_48430907079938756,fake_1137902390679808,fake_34412454921914737unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_5490680661167049,fake_9010011753464402,fake_15111527138568115,fake_6720260818321364,fake_4974649968376741result, different first party:fake_32776140390463837,fake_6504799076535981,fake_5181377711619153,fake_408867162167587,fake_9397177605943396unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_4731919831854967,fake_9743435069527882,fake_8910597114540044,fake_4281916457038477,fake_773999145257243result, different first party:fake_1882843474037159,fake_7075818996062826,fake_01930202742214271,fake_6107176992071621,fake_38800100900376067unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_8919835870065644,fake_09401998413291346,fake_2369129217589485,fake_2295514640556504,fake_6491921573088903result, different first party:fake_07534515097016681,fake_09589348739038672,fake_14439794568858866,fake_028815283289099547,fake_29074152722996427unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_15612947356419493,fake_14064763539077352,fake_973118752995801,fake_01568890949942503,fake_2747235944674129result, different first party:fake_47241023349857847,fake_08392673952351859,fake_6404076169397679,fake_10386815178938069,fake_04967718122878284unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_05043666538509406,fake_8770051298159698,fake_4734819511609163,fake_12522292414825276,fake_0639656809295579result, different first party:fake_0636353599214119,fake_5128133871054479,fake_6207717487023445,fake_847116350986443,fake_9301412944106957unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party: fake_7137302851983749result, different first party: fake_506402076790297unsupported: falsepassed: truetest failed: false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_4549135921627503,fake_6336523240325163,fake_2831380459752899,fake_6430618136212416,fake_9930737337423101result, different first party:fake_9899155880545492,fake_7415434607636813,fake_5477002722046957,fake_8394441796059204,fake_5804758045172189unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same first party:fake_8902634548673958,fake_8279770949116481,fake_882930686664491,fake_2017133143380785,fake_38575942662451257result, different first party:fake_4420492947383563,fake_46331824650016706,fake_5404014753418158,fake_8321000628549335,fake_31617437124822056unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1result, different first party: 1unsupported: falsepassed: falsetest failed: false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same first party: 2, 2, 2, 2, 2result, different first party: 3, 3, 3, 3, 3unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

When a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 2result, different first party: 3unsupported: falsepassed: truetest failed: false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 2, 2, 2, 2, 2result, different first party: 3, 3, 3, 3, 3unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

navigator.storage.getDirectory exposes a location for storing files to web content. In some cases, these files may be shared across tabs.

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:result, different first party: Error: Unsupportedunsupported: truepassed: undefinedtest failed: false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedresult, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party: , , , ,result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party: Error: Unsupportedresult, different first party: Error: Unsupportedunsupported: truepassed: undefinedtest failed: false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt", { create: true });        const stream = await fileHandle.createWritable();        await stream.write(secret);        await stream.close();      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      try {        const root = await navigator.storage.getDirectory();        const fileHandle = await root.getFileHandle("secret.txt");        const file = await fileHandle.getFile();        return file.text();      } catch (e) {        throw new Error("Unsupported");      }    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

HTTP/1.x are the classic web connection protocols. If these connections are re-used across websites, they can be used to track users.

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party:unsupported: falsepassed: truetest failed: false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party:unsupported: falsepassed: truetest failed: false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

HTTP/2 is a web connection protocol introduced in 2015. Some browsers re-use HTTP/2 connections across websites and can thus be used to track users.

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party:unsupported: falsepassed: truetest failed: false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party:unsupported: falsepassed: truetest failed: false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});    }read: async () => {      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});      return await response.text();    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

HTTP/3 is a new standard HTTP connection protocol, still in draft but widely supported by browsers. If it is not partitioned, it can be used to track users across websites.

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:0f4e2f615a2a92e7eec9033b6a2ac9a9,6e0102d3f90c1c76934759d924520081,39e12087ba12002afa4d0b682c313b49,e1c4be0d0f771be50f94c1de92bcd6e1,4ae88fd9fdb9c58787dd5d8dce63f1e1result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:c14ab0368e0868ecf3a945c9c7cf1ad9,aa573b3a6870fdcd177158aefb4eb6af,e0a909bc31276d71b3eed3cef7ec95a4,441529af42ba2b435eb55225d3304d23,result, different first party: , , , ,unsupported: false, false, false, false, truepassed: true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party: d88eca30b1e015c4aaa4db9e93cddd6bresult, different first party: 519e8fa53996cf3e0fe23018b4dd2649unsupported: falsepassed: truetest failed: false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:eee427739e11a0f65289d447e1cc66af,804242032d13442433453d1cb383d7ae,7f22431ee4153d6c2aa7659f1cc25572,9defab13b23303ceb892e9cb469a3472,c00fd94dc5bbb40736653b13cdf4d5b9result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:1b624547ba33d51f9387478edb440c05,1706a4a28faf668cf62469ebc560f7ba,423e8c468db84c50fe148e9b3cd9b18b,a6e8f7d6318765a041b56e2dd9f2152a,7f9c207a796b6593b7776d120bcb4445result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:2d71b3fbc365f20ea87da19e16cb8552,a586d9a5f6a83b757c9b3602f0c389f5,ebe3df2ac9e65761f511c840504b1aa0,93cafab526b832b6a43fb931a7f5ca38,2daab9e4e7a783099e47069f81cac25eresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:0064fbe7a104d9b68ccb289afada2d20,397747719d52d75f8171302afb736e43,a43e3a0d4a5f35d576e08bbbec6694c3,3b330a98329a9b9eb3ee8946ed59a5e9,2ba6c9c3410820323d8c28a7e41d9e5dresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:ae93ceedf1372562eeaa47ceb5140689,1e82f03c01824ef69a11ada78bbc2589,dc47407b1710023e08c02da724ba892b,ff30c92d2e6797e338870c5569fc8b59,24a1c072826f6f589e5db0235e42761aresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:f12d3ffb4dcd60840c8249e7d911c726,a973ad0a27c2d2737b1f0af36a4f8cc0,15de7cd2f9d84c01fb0b6ef6f5da5ae0,883a6f0042c06aa03c07351183785987,d899246e879c4e4434e1e5ddb32f710dresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:result, different first party:unsupported: truepassed: undefinedtest failed: false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:fa626d4a78fd77a43687e63485349999,bc73ea287339b193fa3b37572c255285,da3c26beb67a29ed9fa0c3bcfebe331a,090d894a7ad13b22d75836be4e198e60,07a9c9d3fc2d45df499fb5b09216e3a3result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Ensure that we can switch over to h3 via alt-svc:      for (let i = 0; i<3; ++i) {        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});        await sleepMs(500);      }      // Are we now connecting over h3?      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});      let text = await response.text();      // Empty response text indicates we are not connecting over h3:      if (text.trim() === "") {        throw new Error("Unsupported");      }    }read: async () => {      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);      return await response.text();    }result, same first party:f5b557e8f4ca1082b96b9e14978ceea6,062f731a09422c96b907082dd32e9caa,504d91d4a3471bba9bc7b3a8a6693fa1,dbb6767485b775131a478e7c7f54e9b0,f2df907ee70e0673576743aab204e96aresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The HTTP Strict-Transport-Security response header allows a website to signal that it should only be accessed via HTTPS. The browser remembers this directive in a database, but if this database is not partitioned, then it can be used to track users across websites."

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party: Used http, Used http, Used http, Used http, Used httpunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not testedresult, different first party: Used httpunsupported: falsepassed: truetest failed: false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party: Used http, Used http, Used http, Used http, Used httpunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: nullread: nullresult, same first party: , , , ,result, different first party:HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expectedunsupported: , , , ,passed: true, true, true, true, truetest failed: false, false, false, false, false

write: nullread: nullresult, same first party: , , , ,result, different first party:HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expectedunsupported: , , , ,passed: true, true, true, true, truetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party: Used http, Used http, Used http, Used http, Used httpunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: nullread: nullresult, same first party: nullresult, different first party: HTTPS used by default; no HSTS cache issue expectedunsupported: nullpassed: truetest failed: false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The HTTP Strict-Transport-Security response header allows a website to signal that it should only be accessed via HTTPS. The browser remembers this directive in a database, but if this database is not partitioned, then it can be used to track users across websites."

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party: Used http, Used http, Used http, Used http, Used httpunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not testedresult, different first party: Used httpunsupported: falsepassed: truetest failed: false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party: Used http, Used http, Used http, Used http, Used httpunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: nullread: nullresult, same first party: , , , ,result, different first party:HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expectedunsupported: , , , ,passed: true, true, true, true, truetest failed: false, false, false, false, false

write: nullread: nullresult, same first party: , , , ,result, different first party:HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expected,HTTPS used by default; no HSTS cache issue expectedunsupported: , , , ,passed: true, true, true, true, truetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party: Used http, Used http, Used http, Used http, Used httpunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: nullread: nullresult, same first party: nullresult, different first party: HTTPS used by default; no HSTS cache issue expectedunsupported: nullpassed: truetest failed: false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: set HSTS flagread: read HSTS flagresult, same first party: not tested, not tested, not tested, not tested, not testedresult, different first party:Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to https,Upgraded to httpsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

An iframe is an element in a web page than allows websites to embed a second web page. Caching of this web page could be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

Caching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 2result, different first party: 3unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 2, 2, 2, 2, 2result, different first party: 3, 3, 3, 3, 3unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: undefinedunsupported: falsepassed: truetest failed: false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party:Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecureunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party: Error: IDBFactory.open: The operation is insecureunsupported: falsepassed: truetest failed: false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: nullunsupported: falsepassed: truetest failed: false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party:Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party: Error: The operation is insecure.unsupported: falsepassed: truetest failed: false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

navigator.locks (only supported in some browsers) allows scripts on multiple tabs to coordinate. If this API is not partitioned, it can be used for cross-site tracking.

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party:Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party:Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name')unsupported: falsepassed: truetest failed: false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party:Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party:Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this contextunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party:Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this contextunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party:Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this context,Error: LockManager.query: query() is not allowed in this contextunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party:Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party:Error: undefined is not an object (evaluating 'queryResult.held[0].name'),Error: undefined is not an object (evaluating 'queryResult.held[0].name'),Error: undefined is not an object (evaluating 'queryResult.held[0].name'),Error: undefined is not an object (evaluating 'queryResult.held[0].name'),Error: undefined is not an object (evaluating 'queryResult.held[0].name')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party: Error: LockManager.query: query() is not allowed in this contextunsupported: falsepassed: truetest failed: false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party:Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (navigator.locks) {        navigator.locks.request(key, lock => new Promise((f,r) => {}));        let queryResult = await navigator.locks.query();        return queryResult.held[0].clientId;      } else {        throw new Error("Unsupported");      }    }read: async () => {      if (navigator.locks) {        let queryResult = await navigator.locks.query();        return queryResult.held[0].name;      }    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party:Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name'),Error: Cannot read properties of undefined (reading 'name')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: Error: No requests receivedresult, different first party: Error: No requests receivedunsupported: truepassed: undefinedtest failed: false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different first party:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different first party:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different first party:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: Error: No requests receivedresult, different first party: Error: No requests receivedunsupported: truepassed: undefinedtest failed: false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

Caching of scripts in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 2result, different first party: 3unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 2, 2, 2, 2, 2result, different first party: 3, 3, 3, 3, 3unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The ServiceWorker API allows websites to run code in the background and store content in the browser for offline use. If a ServiceWorker can be accessed from multiple websites, it can be abused to track users across sites.

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party:<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party:<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party:result, different first party:unsupported: falsepassed: undefinedtest failed: true

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party:<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party: , , , ,result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: undefinedtest failed: true, true, true, true, true

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party: , , , ,result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: undefinedtest failed: true, true, true, true, true

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party:Error: navigator.serviceWorker is undefined,Error: navigator.serviceWorker is undefined,Error: navigator.serviceWorker is undefined,Error: navigator.serviceWorker is undefined,Error: navigator.serviceWorker is undefinedresult, different first party:Error: navigator.serviceWorker is undefined,Error: navigator.serviceWorker is undefined,Error: navigator.serviceWorker is undefined,Error: navigator.serviceWorker is undefined,Error: navigator.serviceWorker is undefinedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party:<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party: , , , ,result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: undefinedtest failed: true, true, true, true, true

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party: Error: navigator.serviceWorker is undefinedresult, different first party: Error: navigator.serviceWorker is undefinedunsupported: truepassed: undefinedtest failed: false

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party:<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      if (!navigator.serviceWorker) {        throw new Error("Unsupported");      }      let registration = await navigator.serviceWorker.register(        'serviceWorker.js');      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      await fetch(`serviceworker-write?secret=${key}`);    }read: async () => {      console.log("trying to register the serviceworker now...");      const registration = await Promise.race([        navigator.serviceWorker.register('serviceWorker.js'),        sleepMs(500)      ]);      if (registration === undefined) {        // We timed out or otherwise failed.        throw new Error("ServiceWorker registration failed");      }      console.log(registration);      await navigator.serviceWorker.ready;      console.log("service worker ready");      await sleepMs(100);      let response = await fetch("serviceworker-read");      return await response.text();    }result, same first party:<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->,<html><head><title>404 Not Found</title></head><body><center><h1>404 Not Found</h1></center><hr><center>nginx/1.24.0 (Ubuntu)</center></body></html><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page --><!-- a padding to disable MSIE and Chrome friendly error page -->result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The SharedWorker API allows scripts from multiple tabs to share a background thread of computation. If SharedWorker is not partitioned, then it can be abused to shared data between websites in your browser.

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: Error: Unsupportedunsupported: falsepassed: truetest failed: false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:Error: no SharedWorker message received,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: , true, true, true, truetest failed: true, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party:Error: SharedWorker constructor: StorageAccess denied.,Error: SharedWorker constructor: StorageAccess denied.,Error: SharedWorker constructor: StorageAccess denied.,Error: SharedWorker constructor: StorageAccess denied.,Error: SharedWorker constructor: StorageAccess denied.unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party: Error: SharedWorker constructor: StorageAccess denied.unsupported: falsepassed: truetest failed: false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        let worker = new SharedWorker("supercookies_sharedworker.js");        worker.port.start();//        console.log("worker", worker);        const messagePromise = new Promise((resolve) => {          worker.port.onmessage = (e) => resolve(e.data);        });        worker.port.postMessage(secret);        await messagePromise;      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let worker = new SharedWorker("supercookies_sharedworker.js");      worker.port.start();      const messagePromise = new Promise((resolve, reject) => {        worker.port.onmessage = (e) => resolve(e.data);        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);      });      worker.port.postMessage("request");      const message = await messagePromise;      if (message === "none") {        throw new Error("Unsupported");      }      return message;    }result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The TLS protocol is used by HTTPS to make connections secure. If the browser were to re-use a TLS session, then the session ID could be used to track users across websites.

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:e3cd006292e2552efbd0d40c2710e1b8d94c9d5174acb5932fc13f982fd244f0,f8225feab3f711e3ad022b3f51d77a0b5690b1ccc1cae726edac3105f2c7775a,ee23b86a41cd5463edc1a26b296a9565afd4b9febc729b66258243657712ca05,15984b9ecd8f0b90d49598fb1e9a4e4a7d460d8d1b6e0c947ea5fbf38a268f34,3056704ad5b3e17c56c565c384a53ffa951170f90106780e334d05a64c31c3caresult, different first party:1147e8810fae2523f46d1b3b724d61466778d203091f3e060e3c7b73bce6b365,a5b4a8d518091ccebe02853c964ce3696b6f08608b4ce365f3850c2dd27b721c,2947ec3f4b39ccd04e1e4c6779d3c7094b10e9cc8a60cb5e7fc127fb75cbc872,e50092f5c4efb66ba0ab6db0d09aed610c299acb0b144488cf01e04015cc3528,178db3d7dc4c676a24a92d59d30211eb1c691c3280e621c9226d3ed7d5c671d7unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:19544db3c33db10813613cbe54922868792bde1483db7d40c66fae7de05d4755,e695c81488e21f33758394755c02780605951fb4472afde212bc100915a508e9,08c6eacd49b37068779b744675cc63e76bc5a1bdd77620382b03a9aef21f236b,f893e10488dc0377a76fecda6ea2982f32d5c43ff1291eb99cbb9d010153496d,c7055819b8e79df54a91f114b9b0d7b78faff69c8a7cafbe5b3c461e499cec8cresult, different first party:aca239b7d4f11529529845ad01d08f7b1d6388cd032a089e71f216e8cb24227b,0d35e51b3b35463d7e2c8c9ac4113f5b8a07c89c0e454e252c99bbd5cc224202,9b8098f5b824ded35ae29a7da647c1eda0446d4d9290085d22c97ba3722434ee,31134aa04d548b18bf4c001618c49d472497eef9ddd110bee0440d61562b52bf,6f6c875d56dd099e2bd0bf4653a881e4942e7a6407f4f66d7f8e77e89c244c64unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party: 55dead5f578cc39d129ce72cc73f4c18d610b4254edd015680a624970af93dabresult, different first party: 6cc5d4c3c38ef2de8eec42d2e80600598629f3a1b7dc4f6c420b6859646dc6e6unsupported: falsepassed: truetest failed: false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:227ae5f96333a131e8e7f349e7e2afc4dcd4406504510356f782660fb4b0a617,a083b55b54703ad43c266d01f60b94368ed05feed825064ef993f76667d81229,454b032b02b86dc919be96b260a965a8b921d7767ddfabc2eec0be583751e0f4,d1fc4228b99ff6d97717bc831f200a60b0e5036de3735e7a9f8e861d3fbf6cd0,9b40022ae7ed451f155dd5a523c454fcebeff2fcb222cd632567e6c826cf6318result, different first party:151795368f0415f405439e5bcf1690fac013a36d001aa153a3fe1371c3fa5c23,ec0b3454b73ff1faedca528cfffcd1ca7cdaf9e9cc7415302f7c762b145afed3,242d1f25255381792421db7b9ca037a901d9b71aad12bbeb74a674f257ee81d8,61c4239ce16b9356d5f2f444b1c6f7e484c17910c2fc0231ec645240dc38fd4a,9e17827d8aff3d090b1acb51fc68886458535197d1ad4b9e8e5d835cf6cf6395unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:6d166444c7049d7b9893188c6cf8a812a3fdf044c9cbc260e1497111107fbf24,78d26d42468a507ff21fbd58b45b5e65ec4d30931264b68c63c162fcbc25cd86,85d8e037605af1d5faea36a62df4ddaf2724486df5062c1f3f7cf344f05ed08d,4bb54b3f3f7adf9197f9949b2932dbea00be0245849c8106a2aaea46f97745e2,880110fab971575157b113c90faa5f01db683b0f3319ef07064a8c0f9a27c21cresult, different first party:949387165c61e55c92191775b2fdab136e3c6e21ca894c32c2f2999f833b6bbd,4b9a1aa06a3c124294716bbbcd1925c384bea55c81c0c953fd6a4cacd6ff1cf5,55054449853fd7355decd16f8bacef8060c898c48cfd0415fe6b8facec1264f1,43924aee83348d46f3b537100ecca55aa11d8fb3a48650b03b486eb38505d15a,0949a32d4d6ac7171b2ceed117d9367bc5fd2846c316132931bc36fcfbe5b9a3unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:a437fa5036f61fd46f5a2e0fa8cd039f019f5dfc027718f7220d7569b5acd575,5105737d5dd6d61a087387432e680e98004d6df91b9dad415099ebe582ee8746,9b14938572a2cfbbc220ec6f3ac9f713d86dfecc13376ab32cafd920fe25fa72,8b07ef1bcd443cc2a7c35efe94fe8f57b9af31f3629dd6ec77e0908aa7dd225a,5683505e136cb43a3de10cc924e552852e93a9b540102625d93e8a5966b2dce7result, different first party:0504b4213c6c158e51f10c324337e185ec5b3800de1db9c09db7a679736d2444,3e4f07b3ce1221839bd2536cc03252c1c7d6d25478e5bdcb358c8a3ae6d2e57e,1f88c1ad8c17de7f5738fa9caf1d0df841dd011f600552f70fdd9673734cbc2d,9c5dfe3db7cf0e86df34aab4cf8a44a4a220b3c9f04ee497d9ba8a10fc007151,0b18e82e63b9e06db8b26ab5883ce9b89ff30d92ede9f187927b05c8f214fd1cunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:b89c88833228bbc8d5664c5204ebf84f74c71d98c8c4d8fd423172a2ff45e5cb,1b2ebbecd9c7ff10fc93dd0c3ba7fc979bd78b48988b10d792d4fa92b259948c,6eea80da5ba977b100f20bd6ce521e3dea85a0013963c247002beccf90c4627d,edbfc3ecc62a523d02fa7050cb090e9082dea0c6e636830281e921720a682aa7,0e7f4513b7606b6edca9429de0234a3e3d89c4a75576f8f5e5ace0e8fad0050eresult, different first party:b224f17b1cff5bbff1512c5abdb2cd8f7f7f80385d57105068ce8b8492fa4f86,627fcdbf4a876cda8e5e81026c956a0629fa1aa73ab5a2623bd7a8cea4db89e3,b3c0b8858d5379a880e72420fdf2fe49adbce23ccc3a24e3a0bdf9a6e84c4bc9,35a3c8d4eaae848851c539d0d1ec2d4c5337c4e9dceee46050e23ab76a2e7ac4,361dbaee63e4aff342dbcf1d820ba64bbc454ff2385d3b9fac528b1a414ab803unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:a7cbdaa11edf83c89550f7e28e11fc8effc84b190d17b96abd3527c3ec1d92d5,c04c4325efdf1e9119ee35f6bc16eca0f94dc6f663385040172651b1cf9369b4,0edfd9d6b835ab0f5e67430f883a25cc669d26130d3f838ca0d6ef6c2c1371bf,7c513a623626ef318a66b11c6857c73d3839ea29fee20761666ef391f3bd7e1a,aeaca37d54533be6c8dc5229bbcdb35b2cd28cfa1afc113bdc69b2e4d916a280result, different first party:9a321b5e0e773e11794344d314366cdeffc5c0071ecbf873fbe886a4c18131d1,f8ee347b521292b369e78625e89cf3060726fbf0c9e500a70b2db3bf6cb71bd7,4781bd4d0f45ce882abd391fdcf51f396a0064ea0e6367757c3a52237741ef72,82bad058f40df910a2710a180bb9501bca428ef2f3bf1fd37d0e325628186c38,22060cbd0b9ed6b0d7a22ac768cd9326d7c7e1c2683e60ee38fb403ef432a32funsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:fde54322ac4ed720403dcf144be927c202de0c5384557d73ad4fcdb86a7b0543,cc34439726a90d8d1743979ad851ef700d86b1c4dc06f359eecc102ff1d22a9b,57df7b6ec524bc3778a0fc0ab294f3942725dec37adb6c8e7a79c8c468bc01b0,1cc20fd49c8f6097eaf0209122c247bd0f7764001d065b54c56ff4a97fc6ef88,fceec51ddda3b39ceff36c30074da46b5927ec4701282389f3e5199264c8ac02result, different first party:cbeeee649ca1a7aeb3933385b4b081ae9c6d93df03176eec56574b80d317f43b,7d3a6039e3087699c724270bf67fcd4fb87f81ccd2be6a4c3e27a56dcfdedeb1,23f8c9cfac55d7daab04407a2fdf9f74ebdaf4eea034e40ebc96c7fc8a7828c6,6ebcd3d4831e3c03fb36adeb3dc082dc5440c6a0171294a58aa04e5296d5fa1e,0ab70f6776ddacd9285815997bf279ae5eecfe07856c123f4ac9a077233c38b4unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party: a06a5772643fafd9fa7c99901f845f008093fae25faea30a9059930c63fb4751result, different first party: 997ba3c7ae071d38dc671ec0c92b2f7f862f5c0fe36840bb090fc9751a383914unsupported: falsepassed: truetest failed: false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:b3b6c4cf3303da3ae5c7ef9191ee719ad86a494c875cb5cecf337d8665562244,64cd4605a78b5c2ea0b33353e3e844207a48cc33d072055a74581bc44ec0c8bb,dce9085aab4bd607f4a374aab05d5d3a7d48e74aa777e9eba2dda56e1bf1f6f3,9273441e2479797116fd19c76a2b2f4928958871e4bb456b6bc34273dcf65bc3,125f014fcf2fc3b9005d49fbdcd9a5b49f128328a896ef6ddc2ae4974b2d2733result, different first party:8d3d2106c2c39e1abf35e24dd1c34f225709fb5e712be58cfc058298e8ec552f,6eb6dcea57933c740c4980a96ec0c9e889fba7be7c9439cf1ab532ec9ce81781,cab81c856387d0d94497e2dc0d9a00f89fc68410f7169b80a5066b772666fcf2,61d020a4b05d292e6884828fd7e5649460145a54250c6378b3b0a468ab3d5a41,ed5ae4c8d0cd3d88ec63819cd30a650a1d3dfcb361ef11980c78898f53fbf8aaunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }read: async () => {      let results = await fetch("https://tls.privacytests2.org:8900/");      return (await results.json()).sessionId;    }result, same first party:aa10696fd4e21435cf0c44487072b89d3a224552491b24038e87d9d75247fa9a,058aa9ef19588ca0efab0be1684f3e12ec09455efa06276c3fcb939e57d34d1b,ec639c383d78fefae524057b42891fcfc890041a482071c46316d49ab8ecb4c7,f4f13b62549948066a2c53ce554c808819fb6ac39a772075a2681f0e74fb399a,450ec0c141a73693e622630f01b924fdecdfb989b8e5da35276eefb6eec82b87result, different first party:bea4a13152a56df3283d9ee77feca01bbc6c7c4efd5606f56c2f046ce9a51c34,8fd3b5b938b7a1f9845b93f2200d1cf0f84c5e01982f9c6b7b1c70cfe3e24101,66966eb12fee94e5bbc3dc3ba2c59361208c540d5dca80d09cdadb4726d09e92,bfc3796fd479ab825d1ad2d6ad9a60cee406660ec46b05179798975deb032da1,ef0165cbcf57996e136199e043191d6092a881bbb1fe1ab090875e3df4baf020unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1result, different first party: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same first party: 1, 1, 1, 1, 1result, different first party: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The Referer [sic] request header is a mechanism used by browsers to let a website know where the user is visiting from. This header is inherently tracking users across websites. In recent times, browsers have switched to a policy of trimming a referrer to convey less tracking information, but Referer continues to convey cross-site tracking data by default.

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party: https://test-pages.privacytests2.org/result, different first party: https://test-pages.privacytests2.org/unsupported: falsepassed: falsetest failed: false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party: https://test-pages.privacytests2.org/result, different first party: https://test-pages.privacytests2.org/unsupported: falsepassed: falsetest failed: false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => { /* do nothing */ }read: () => document.referrerresult, same first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/result, different first party:https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/,https://test-pages.privacytests2.org/unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The sessionStorage API is similar to the localStorage API, but it does not persist across tabs or across browser sessions. Nonetheless, it can be used to track users if they navigate from one website to another. This tracking can be thwarted by partitioning sessionStorage between websites.

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:e7085635-2c69-4e98-92d3-97e4c73afa2f,dad47994-1478-4269-bc67-9d5be7279695,a224b08b-56ca-430a-8291-a1391ce3f527,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:99f0a2bf-b41a-4758-8d51-b9c5d07dd116,9e792e5f-2682-45df-a4b6-9926c1368572,96cb1992-e972-4aef-8062-ef9c5ed16a01,be33e986-4227-4dad-98ab-849158191238,d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party: nullunsupported: falsepassed: truetest failed: false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:026115d8-5ec8-4705-b68d-299ea05d729f,b33c419d-acf6-4795-95e0-d5d753f2f16d,6a79070f-7300-4f0a-b3e4-67db8452282d,fc4e16e7-ac2e-48a9-8623-332158912d29,311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:a89ceebb-1801-46fc-bbfa-9268cd1e86b8,3c6d0906-4d80-439c-9124-ff2647fc503f,29934d34-345f-4b44-91a5-4cfc4705276b,c261a896-1dbf-455d-8a32-c51b15883279,4befec68-5b8d-4639-b156-03db7501a173result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:15e21312-33db-4994-b766-baad8032803f,7ccbfb90-229d-427c-9f22-79caffc2fec3,ab247bb9-7408-43c0-81f4-22f7335617f7,1cc5af75-9209-4c31-a70b-5f98374d6544,f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:e64ec357-7007-4dab-a6fa-6650afbb1b92,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,f2c54d89-4429-43be-9044-840a1c275e7f,91894484-f7cc-4015-ae96-635239333863,d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,299e3cd4-7953-4f77-801f-8985b822ac24,aad11fab-6660-48f9-b28d-4b2ee45a44df,d31fb840-54e6-4419-b2ca-f532e60327ac,8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,fe4b6d38-97a5-47e0-8ce9-abd6b175891b,3ac91718-3eba-45e8-aceb-765d0391821b,f2d6741d-a215-4cac-a81a-dec44031672d,576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party: nullunsupported: falsepassed: truetest failed: false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:24441439-f1db-4c84-bc96-50682c4e643e,6d1c53c8-70cf-47eb-9a21-0ba706352479,5894b594-2a38-4d3a-be5d-e53e01ad93d1,e198d1f6-c1a6-4343-9907-302129e685e7,bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => sessionStorage.setItem("secret", secret)read: () => sessionStorage.getItem("secret")result, same first party:9d7140bd-04e0-44f3-b6d6-e0234d82e99b,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,32f534ec-f0c9-4fb9-a393-c743feebc30e,085080b8-ac7e-4d13-b00e-fceb219d3dac,e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

The window.name API allows websites to store data that will persist after the user has navigated the tab to a different website. This mechanism could be partitioned so that data is not allowed to persist between websites.

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_e7085635-2c69-4e98-92d3-97e4c73afa2f,name_dad47994-1478-4269-bc67-9d5be7279695,name_a224b08b-56ca-430a-8291-a1391ce3f527,name_ed625f5b-53f1-45e2-b9d8-f1afa4b755d4,name_54ad99c6-a8ab-4b8b-957e-aaa49d517db0result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_99f0a2bf-b41a-4758-8d51-b9c5d07dd116,name_9e792e5f-2682-45df-a4b6-9926c1368572,name_96cb1992-e972-4aef-8062-ef9c5ed16a01,name_be33e986-4227-4dad-98ab-849158191238,name_d1bff213-a9f5-41c3-a065-c8b074cff472result, different first party:name_99f0a2bf-b41a-4758-8d51-b9c5d07dd116,name_9e792e5f-2682-45df-a4b6-9926c1368572,name_96cb1992-e972-4aef-8062-ef9c5ed16a01,name_be33e986-4227-4dad-98ab-849158191238,name_d1bff213-a9f5-41c3-a065-c8b074cff472unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party: name_fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599result, different first party:unsupported: falsepassed: truetest failed: false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_026115d8-5ec8-4705-b68d-299ea05d729f,name_b33c419d-acf6-4795-95e0-d5d753f2f16d,name_6a79070f-7300-4f0a-b3e4-67db8452282d,name_fc4e16e7-ac2e-48a9-8623-332158912d29,name_311d701c-ad7e-4aa7-84a2-afdf4a4a400bresult, different first party:name_026115d8-5ec8-4705-b68d-299ea05d729f,name_b33c419d-acf6-4795-95e0-d5d753f2f16d,name_6a79070f-7300-4f0a-b3e4-67db8452282d,name_fc4e16e7-ac2e-48a9-8623-332158912d29,name_311d701c-ad7e-4aa7-84a2-afdf4a4a400bunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_a89ceebb-1801-46fc-bbfa-9268cd1e86b8,name_3c6d0906-4d80-439c-9124-ff2647fc503f,name_29934d34-345f-4b44-91a5-4cfc4705276b,name_c261a896-1dbf-455d-8a32-c51b15883279,name_4befec68-5b8d-4639-b156-03db7501a173result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_15e21312-33db-4994-b766-baad8032803f,name_7ccbfb90-229d-427c-9f22-79caffc2fec3,name_ab247bb9-7408-43c0-81f4-22f7335617f7,name_1cc5af75-9209-4c31-a70b-5f98374d6544,name_f1e4b993-6e6c-430d-bd4c-f9214ee02e71result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_e64ec357-7007-4dab-a6fa-6650afbb1b92,name_ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56,name_f2c54d89-4429-43be-9044-840a1c275e7f,name_91894484-f7cc-4015-ae96-635239333863,name_d4713458-e4ff-458e-b8a8-0a3562d0441bresult, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,name_299e3cd4-7953-4f77-801f-8985b822ac24,name_aad11fab-6660-48f9-b28d-4b2ee45a44df,name_d31fb840-54e6-4419-b2ca-f532e60327ac,name_8003e0ac-cbd3-4236-932f-a79792d54b62result, different first party:name_3ae57aff-59cf-478f-83e7-0ce6e2ef84fd,name_299e3cd4-7953-4f77-801f-8985b822ac24,name_aad11fab-6660-48f9-b28d-4b2ee45a44df,name_d31fb840-54e6-4419-b2ca-f532e60327ac,name_8003e0ac-cbd3-4236-932f-a79792d54b62unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_c0150e2b-e0d0-41b9-b45d-d902a1eb8b52,name_fe4b6d38-97a5-47e0-8ce9-abd6b175891b,name_3ac91718-3eba-45e8-aceb-765d0391821b,name_f2d6741d-a215-4cac-a81a-dec44031672d,name_576d3332-f9c6-455d-bddd-b3b643b6c552result, different first party: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party: name_49fe77ef-a8ac-4213-90fb-9b81cb45fd81result, different first party:unsupported: falsepassed: truetest failed: false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_24441439-f1db-4c84-bc96-50682c4e643e,name_6d1c53c8-70cf-47eb-9a21-0ba706352479,name_5894b594-2a38-4d3a-be5d-e53e01ad93d1,name_e198d1f6-c1a6-4343-9907-302129e685e7,name_bf62e3cc-149e-4225-8d7b-3b8b3b338e10result, different first party:name_24441439-f1db-4c84-bc96-50682c4e643e,name_6d1c53c8-70cf-47eb-9a21-0ba706352479,name_5894b594-2a38-4d3a-be5d-e53e01ad93d1,name_e198d1f6-c1a6-4343-9907-302129e685e7,name_bf62e3cc-149e-4225-8d7b-3b8b3b338e10unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => window.name = "name_" + secretread: () => window.nameresult, same first party:name_9d7140bd-04e0-44f3-b6d6-e0234d82e99b,name_5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,name_32f534ec-f0c9-4fb9-a393-c743feebc30e,name_085080b8-ac7e-4d13-b00e-fceb219d3dac,name_e74254c5-9034-45cd-b7ba-b7db726e55abresult, different first party:name_9d7140bd-04e0-44f3-b6d6-e0234d82e99b,name_5a8cb80f-21db-4a7c-bd79-071d7e26aeb7,name_32f534ec-f0c9-4fb9-a393-c743feebc30e,name_085080b8-ac7e-4d13-b00e-fceb219d3dac,name_e74254c5-9034-45cd-b7ba-b7db726e55abunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Checks to see if the browser stops loading an insecure website and warns the user before giving them the option to continue. Known as HTTPS-Only Mode in some browsers.

passed: false, false, false, false, falseresult:Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded

passed: false, false, false, false, falseresult:Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded

passed: falseresult: Insecure website loaded

passed: false, false, false, false, falseresult:Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded

passed: false, false, false, false, falseresult:Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded

passed: true, true, true, true, trueresult:Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded

passed: true, true, true, true, trueresult:Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded

passed: false, false, false, false, falseresult:Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded

passed: false, false, false, false, falseresult:Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded

passed: trueresult: Insecure website never loaded

passed: false, false, false, false, falseresult:Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded

passed: false, false, false, false, falseresult:Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded

Checks to see if an insecure address entered into the browser's address bar is upgraded to HTTPS whenever possible.

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: falsepassed: false

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: truepassed: true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

Checks to see if the user has clicked on a hyperlink to an insecure address, if the browser upgrades that address to HTTPS whenever possible.

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: falsepassed: false

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: truepassed: true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

upgraded: true, true, true, true, truepassed: true, true, true, true, true

Checks to see if the browser attempts to upgrade an insecure address for an image to HTTPS whenever possible.

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: trueresult: upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: trueresult: upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

Checks to see if the browser attempts to upgrade an insecure address for an script to HTTPS whenever possible.

passed: true, true, true, true, trueresult: blocked, blocked, blocked, blocked, blocked

passed: true, true, true, true, trueresult: blocked, blocked, blocked, blocked, blocked

passed: trueresult: blocked

passed: true, true, true, true, trueresult: blocked, blocked, blocked, blocked, blocked

passed: true, true, true, true, trueresult: blocked, blocked, blocked, blocked, blocked

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: upgraded, upgraded, upgraded, upgraded, upgraded

passed: true, true, true, true, trueresult: blocked, blocked, blocked, blocked, blocked

passed: true, true, true, true, trueresult: blocked, blocked, blocked, blocked, blocked

passed: trueresult: upgraded

passed: true, true, true, true, trueresult: blocked, blocked, blocked, blocked, blocked

passed: true, true, true, true, trueresult: blocked, blocked, blocked, blocked, blocked

Encrypted Client Hello (ECH) is a new protocol that hides the website you are visiting from third-party network eavesdroppers.

SNI_status: encryptedpassed: true, true, false, true, true

SNI_status: encryptedpassed: true, true, true, true, true

SNI_status: plaintextpassed: false

SNI_status: encryptedpassed: true, true, true, true, true

SNI_status: encryptedpassed: true, true, true, true, true

SNI_status: plaintextpassed: false, false, false, false, false

SNI_status: encryptedpassed: true, true, true, true, true

SNI_status: encryptedpassed: true, true, true, true, true

SNI_status: plaintextpassed: false, false, false, false, false

SNI_status: plaintextpassed: false

SNI_status: encryptedpassed: true, true, true, true, true

SNI_status: encryptedpassed: true, false, true, true, true

The Global Privacy Control is an HTTP header that can be sent by a browser to instruct a website not to sell the user's personal data to third parties. This test checks to see if the GPC header is sent by default to the top-level website.

header value: 1passed: true, true, true, true, true

header value: undefinedpassed: false, false, false, false, false

header value: 1passed: true

header value: undefinedpassed: false, false, false, false, false

header value: undefinedpassed: false, false, false, false, false

header value: 1passed: true, true, true, true, true

header value: 1passed: true, true, true, true, true

header value: undefinedpassed: false, false, false, false, false

header value: undefinedpassed: false, false, false, false, false

header value: 1passed: true

header value: undefinedpassed: false, false, false, false, false

header value: undefinedpassed: false, false, false, false, false

The Global Privacy Control is an HTTP header that can be sent by a browser to instruct a visited website not to sell the user's personal data to other parties. This test checks to see if the GPC header is sent to third-party elements on the web page.

sec-gpc: 1passed: true, true, true, true, true

passed: false, false, false, false, false

passed: false

passed: false, false, false, false, false

passed: false, false, false, false, false

sec-gpc: 1passed: true, true, true, true, true

sec-gpc: 1passed: true, true, true, true, true

passed: false, false, false, false, false

passed: false, false, false, false, false

sec-gpc: 1passed: true

passed: false, false, false, false, false

passed: false, false, false, false, false

IP addresses can be used to uniquely identify a large percentage of users. A proxy, VPN, or Tor can mask a user's IP address.

passed: false, false, false, false, false

passed: false, false, false, false, false

passed: false

passed: false, false, false, false, false

passed: false, false, false, false, false

passed: false, false, false, false, false

passed: false, false, false, false, false

passed: false, false, false, false, false

passed: false, false, false, false, false

passed: true

passed: false, false, false, false, false

passed: false, false, false, false, false

Browsers that use Tor can use a different Tor circuit per top-level website.

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: truereadSameFirstParty: Error: UnsupportedreadDifferentFirstParty: Error: UnsupportedtestFailed: false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: falsereadSameFirstParty: 45.134.225.36readDifferentFirstParty: 2001:67c:e60:c0c:192:42:116:196passed: truetestFailed: false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

write: () => {      if (!usingTor) {        throw new Error("Unsupported");      }    }read: async () => {      if (usingTor) {        return ipAddress;      } else {        throw new Error("Unsupported");      }    }unsupported: true, true, true, true, truereadSameFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedreadDifferentFirstParty:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: UnsupportedtestFailed: false, false, false, false, false

The Tor network sends the browser's web requests through a series of relays to hide a user's IP address, thereby helping to mask their identity and location. This test checks to see if the Tor network is being used by default.

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: falsepassed: false

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: truepassed: true

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

IsTorExit: false, false, false, false, falsepassed: false, false, false, false, false

Web pages can detect the presence of a font installed on the user's system. The presence or absence of various fonts is commonly used to fingerprint users.

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: true,true,true,true,true

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: false,false,false,false,false

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: false

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: false,false,false,false,false

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: false,false,false,false,false

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: true,true,true,true,true

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: true,true,true,true,true

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: false,false,false,false,false

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: true,true,true,true,true

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: true

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: false,false,false,false,false

expression: undefineddesired expression: undefinedactual value: undefineddesired value: undefinedpassed: false,false,false,false,false

HubSpot tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

HubSpot tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

HubSpot tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Drip.com email address tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

HubSpot tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Yandex tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

DoubleClick Click ID (Google)

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Facebook Click Identifier

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Google Click Identifier

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

HubSpot tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Mailchimp Email ID (email recipient's address)

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Adobe Marketo tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

MailerLite email tracking

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

MailerLite email tracking

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Microsoft Click ID

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Omeda marketing 'anonymous' customer id

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Omeda marketing 'known' customer id

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Unknown high-entropy tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Adobe Site Catalyst tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Vero tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Vero tracking parameter

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Wicked Reports e-commerce tracking

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Yandex Click ID

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true, true, true, true, true

passed: true, true, true, true, true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

passed: true

value: 8061754823985428passed: false, false, false, false, false

value: 8061754823985428passed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://munchkin.marketo.net/munchkin.js

url: https://munchkin.marketo.net/munchkin.jspassed: true, true, true, true, true

url: https://munchkin.marketo.net/munchkin.jspassed: false, false, false, false, false

url: https://munchkin.marketo.net/munchkin.jspassed: true

url: https://munchkin.marketo.net/munchkin.jspassed: false, false, false, false, false

url: https://munchkin.marketo.net/munchkin.jspassed: false, false, false, false, false

url: https://munchkin.marketo.net/munchkin.jspassed: true, true, true, true, true

url: https://munchkin.marketo.net/munchkin.jspassed: true, true, true, true, true

url: https://munchkin.marketo.net/munchkin.jspassed: false, false, false, false, false

url: https://munchkin.marketo.net/munchkin.jspassed: false, false, false, false, false

url: https://munchkin.marketo.net/munchkin.jspassed: false

url: https://munchkin.marketo.net/munchkin.jspassed: false, false, false, false, false

url: https://munchkin.marketo.net/munchkin.jspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://dpm.demdex.net/ibs

url: https://dpm.demdex.net/ibspassed: true, true, true, true, true

url: https://dpm.demdex.net/ibspassed: false, false, false, false, false

url: https://dpm.demdex.net/ibspassed: true

url: https://dpm.demdex.net/ibspassed: false, false, false, false, false

url: https://dpm.demdex.net/ibspassed: false, false, false, false, false

url: https://dpm.demdex.net/ibspassed: true, true, true, true, true

url: https://dpm.demdex.net/ibspassed: true, true, true, true, true

url: https://dpm.demdex.net/ibspassed: false, false, false, false, false

url: https://dpm.demdex.net/ibspassed: false, false, false, false, false

url: https://dpm.demdex.net/ibspassed: false

url: https://dpm.demdex.net/ibspassed: false, false, false, false, false

url: https://dpm.demdex.net/ibspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://s.amazon-adsystem.com/dcm

url: https://s.amazon-adsystem.com/dcmpassed: true, true, true, true, true

url: https://s.amazon-adsystem.com/dcmpassed: false, false, false, false, false

url: https://s.amazon-adsystem.com/dcmpassed: true

url: https://s.amazon-adsystem.com/dcmpassed: false, false, false, false, false

url: https://s.amazon-adsystem.com/dcmpassed: false, false, false, false, false

url: https://s.amazon-adsystem.com/dcmpassed: true, true, true, true, true

url: https://s.amazon-adsystem.com/dcmpassed: true, true, true, true, true

url: https://s.amazon-adsystem.com/dcmpassed: false, false, false, false, false

url: https://s.amazon-adsystem.com/dcmpassed: false, false, false, false, false

url: https://s.amazon-adsystem.com/dcmpassed: false

url: https://s.amazon-adsystem.com/dcmpassed: false, false, false, false, false

url: https://s.amazon-adsystem.com/dcmpassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://ib.adnxs.com/px?id=178248&t=1

url: https://ib.adnxs.com/px?id=178248&t=1passed: true, true, true, true, true

url: https://ib.adnxs.com/px?id=178248&t=1passed: false, false, false, false, false

url: https://ib.adnxs.com/px?id=178248&t=1passed: true

url: https://ib.adnxs.com/px?id=178248&t=1passed: false, false, false, false, false

url: https://ib.adnxs.com/px?id=178248&t=1passed: false, false, false, false, false

url: https://ib.adnxs.com/px?id=178248&t=1passed: true, true, true, true, true

url: https://ib.adnxs.com/px?id=178248&t=1passed: true, true, true, true, true

url: https://ib.adnxs.com/px?id=178248&t=1passed: false, false, false, false, false

url: https://ib.adnxs.com/px?id=178248&t=1passed: false, false, false, false, false

url: https://ib.adnxs.com/px?id=178248&t=1passed: false

url: https://ib.adnxs.com/px?id=178248&t=1passed: false, false, false, false, false

url: https://ib.adnxs.com/px?id=178248&t=1passed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://bat.bing.com/bat.js

url: https://bat.bing.com/bat.jspassed: true, true, true, true, true

url: https://bat.bing.com/bat.jspassed: false, false, false, false, false

url: https://bat.bing.com/bat.jspassed: true

url: https://bat.bing.com/bat.jspassed: false, false, false, false, false

url: https://bat.bing.com/bat.jspassed: false, false, false, false, false

url: https://bat.bing.com/bat.jspassed: true, true, true, true, true

url: https://bat.bing.com/bat.jspassed: true, true, true, true, true

url: https://bat.bing.com/bat.jspassed: false, false, false, false, false

url: https://bat.bing.com/bat.jspassed: false, false, false, false, false

url: https://bat.bing.com/bat.jspassed: false

url: https://bat.bing.com/bat.jspassed: false, false, false, false, false

url: https://bat.bing.com/bat.jspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://static.chartbeat.com/js/chartbeat.js

url: https://static.chartbeat.com/js/chartbeat.jspassed: true, true, true, true, true

url: https://static.chartbeat.com/js/chartbeat.jspassed: false, false, false, false, false

url: https://static.chartbeat.com/js/chartbeat.jspassed: true

url: https://static.chartbeat.com/js/chartbeat.jspassed: false, false, false, false, false

url: https://static.chartbeat.com/js/chartbeat.jspassed: false, false, false, false, false

url: https://static.chartbeat.com/js/chartbeat.jspassed: true, true, true, true, true

url: https://static.chartbeat.com/js/chartbeat.jspassed: true, true, true, true, true

url: https://static.chartbeat.com/js/chartbeat.jspassed: false, false, false, false, false

url: https://static.chartbeat.com/js/chartbeat.jspassed: false, false, false, false, false

url: https://static.chartbeat.com/js/chartbeat.jspassed: false

url: https://static.chartbeat.com/js/chartbeat.jspassed: false, false, false, false, false

url: https://static.chartbeat.com/js/chartbeat.jspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: true, true, true, true, true

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: false, false, false, false, false

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: true

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: false, false, false, false, false

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: false, false, false, false, false

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: true, true, true, true, true

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: true, true, true, true, true

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: false, false, false, false, false

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: false, false, false, false, false

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: false

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: false, false, false, false, false

url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxpassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://securepubads.g.doubleclick.net/static/glade.js

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: true, true, true, true, true

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: false, false, false, false, false

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: true

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: false, false, false, false, false

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: true, false, false, false, false

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: true, true, true, true, true

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: true, true, true, true, true

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: false, false, false, false, false

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: false, false, false, false, false

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: false

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: false, false, false, false, false

url: https://securepubads.g.doubleclick.net/static/glade.jspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://connect.facebook.net/en_US/fbevents.js

url: https://connect.facebook.net/en_US/fbevents.jspassed: true, true, true, true, true

url: https://connect.facebook.net/en_US/fbevents.jspassed: false, false, false, false, false

url: https://connect.facebook.net/en_US/fbevents.jspassed: true

url: https://connect.facebook.net/en_US/fbevents.jspassed: false, false, false, false, false

url: https://connect.facebook.net/en_US/fbevents.jspassed: false, false, false, false, false

url: https://connect.facebook.net/en_US/fbevents.jspassed: true, true, true, true, true

url: https://connect.facebook.net/en_US/fbevents.jspassed: true, true, true, true, true

url: https://connect.facebook.net/en_US/fbevents.jspassed: false, false, false, false, false

url: https://connect.facebook.net/en_US/fbevents.jspassed: false, false, false, false, false

url: https://connect.facebook.net/en_US/fbevents.jspassed: false

url: https://connect.facebook.net/en_US/fbevents.jspassed: false, false, false, false, false

url: https://connect.facebook.net/en_US/fbevents.jspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://www.google.com/pagead/1p-user-list/

url: https://www.google.com/pagead/1p-user-list/passed: true, true, true, true, true

url: https://www.google.com/pagead/1p-user-list/passed: false, false, false, false, false

url: https://www.google.com/pagead/1p-user-list/passed: true

url: https://www.google.com/pagead/1p-user-list/passed: false, false, false, false, false

url: https://www.google.com/pagead/1p-user-list/passed: false, false, false, false, false

url: https://www.google.com/pagead/1p-user-list/passed: true, true, true, true, true

url: https://www.google.com/pagead/1p-user-list/passed: true, true, true, true, true

url: https://www.google.com/pagead/1p-user-list/passed: false, false, false, false, false

url: https://www.google.com/pagead/1p-user-list/passed: false, false, false, false, false

url: https://www.google.com/pagead/1p-user-list/passed: false

url: https://www.google.com/pagead/1p-user-list/passed: false, false, false, false, false

url: https://www.google.com/pagead/1p-user-list/passed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://google-analytics.com/urchin.js

url: https://google-analytics.com/urchin.jspassed: true, true, true, true, true

url: https://google-analytics.com/urchin.jspassed: false, false, false, false, false

url: https://google-analytics.com/urchin.jspassed: true

url: https://google-analytics.com/urchin.jspassed: false, false, false, false, false

url: https://google-analytics.com/urchin.jspassed: false, false, false, false, false

url: https://google-analytics.com/urchin.jspassed: true, true, true, true, true

url: https://google-analytics.com/urchin.jspassed: true, true, true, true, true

url: https://google-analytics.com/urchin.jspassed: false, false, false, false, false

url: https://google-analytics.com/urchin.jspassed: false, false, false, false, false

url: https://google-analytics.com/urchin.jspassed: false

url: https://google-analytics.com/urchin.jspassed: false, false, false, false, false

url: https://google-analytics.com/urchin.jspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: true, true, true, true, true

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: false, false, false, false, false

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: true

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: false, false, false, false, false

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: false, false, false, false, false

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: true, true, true, true, true

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: true, true, true, true, true

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: false, false, false, false, false

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: false, false, false, false, false

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: false

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: false, false, false, false, false

url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLpassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: true, true, true, true, true

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: false, false, false, false, false

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: true

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: false, false, false, false, false

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: false, false, false, false, false

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: true, true, true, true, true

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: true, true, true, true, true

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: false, false, false, false, false

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: false, false, false, false, false

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: false

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: false, false, false, false, false

url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1passed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://js-agent.newrelic.com/nr-1212.min.js

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: true, true, true, true, true

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: false, false, false, false, false

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: true

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: false, false, false, false, false

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: false, false, false, false, false

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: true, true, true, true, true

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: true, true, true, true, true

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: false, false, false, false, false

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: false, false, false, false, false

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: false

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: false, false, false, false, false

url: https://js-agent.newrelic.com/nr-1212.min.jspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://pixel.quantserve.com/pixel

url: https://pixel.quantserve.com/pixelpassed: true, true, true, true, true

url: https://pixel.quantserve.com/pixelpassed: false, false, false, false, false

url: https://pixel.quantserve.com/pixelpassed: true

url: https://pixel.quantserve.com/pixelpassed: false, false, false, false, false

url: https://pixel.quantserve.com/pixelpassed: false, false, false, false, false

url: https://pixel.quantserve.com/pixelpassed: true, true, true, true, true

url: https://pixel.quantserve.com/pixelpassed: true, true, true, true, true

url: https://pixel.quantserve.com/pixelpassed: false, false, false, false, false

url: https://pixel.quantserve.com/pixelpassed: false, false, false, false, false

url: https://pixel.quantserve.com/pixelpassed: false

url: https://pixel.quantserve.com/pixelpassed: false, false, false, false, false

url: https://pixel.quantserve.com/pixelpassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://sb.scorecardresearch.com/internal-c2/default/cs.js

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: true, true, true, true, true

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: false, false, false, false, false

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: true

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: false, false, false, false, false

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: false, false, false, false, false

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: true, true, true, true, true

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: true, true, true, true, true

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: false, false, false, false, false

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: false, false, false, false, false

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: false

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: false, false, false, false, false

url: https://sb.scorecardresearch.com/internal-c2/default/cs.jspassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://trc.taboola.com/futureplc-tomsguide/trc/3/json

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: true, true, true, true, true

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: false, false, false, false, false

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: true

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: false, false, false, false, false

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: false, false, false, false, false

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: true, true, true, true, true

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: true, true, true, true, true

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: false, false, false, false, false

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: false, false, false, false, false

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: false

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: false, false, false, false, false

url: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsonpassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://t.co/i/adsct

url: https://t.co/i/adsctpassed: true, true, true, true, true

url: https://t.co/i/adsctpassed: false, false, false, false, false

url: https://t.co/i/adsctpassed: true

url: https://t.co/i/adsctpassed: false, false, false, false, false

url: https://t.co/i/adsctpassed: false, false, false, false, false

url: https://t.co/i/adsctpassed: true, true, true, true, true

url: https://t.co/i/adsctpassed: true, true, true, true, true

url: https://t.co/i/adsctpassed: false, false, false, false, false

url: https://t.co/i/adsctpassed: false, false, false, false, false

url: https://t.co/i/adsctpassed: false

url: https://t.co/i/adsctpassed: false, false, false, false, false

url: https://t.co/i/adsctpassed: false, false, false, false, false

Tests whether the browser blocks the page from loading the tracker at https://yandex.ru/ads/system/header-bidding.js

url: https://yandex.ru/ads/system/header-bidding.jspassed: true, true, true, true, true

url: https://yandex.ru/ads/system/header-bidding.jspassed: false, false, false, false, false

url: https://yandex.ru/ads/system/header-bidding.jspassed: true

url: https://yandex.ru/ads/system/header-bidding.jspassed: false, false, false, false, false

url: https://yandex.ru/ads/system/header-bidding.jspassed: false, false, false, false, false

url: https://yandex.ru/ads/system/header-bidding.jspassed: true, true, true, true, true

url: https://yandex.ru/ads/system/header-bidding.jspassed: true, true, true, true, true

url: https://yandex.ru/ads/system/header-bidding.jspassed: false, false, false, false, false

url: https://yandex.ru/ads/system/header-bidding.jspassed: false, false, false, false, false

url: https://yandex.ru/ads/system/header-bidding.jspassed: false

url: https://yandex.ru/ads/system/header-bidding.jspassed: false, false, false, false, false

url: https://yandex.ru/ads/system/header-bidding.jspassed: false, false, false, false, false

Tests whether the browser stops cookies from munchkin.marketo.net from tracking users across websites.

passed: true, true, true, true, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://munchkin.marketo.net/munchkin.jscookieFound: true, true, true, true, true

passed: trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false

passed: true, true, true, true, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, false, false

passed: trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false

passed: true, true, true, true, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://munchkin.marketo.net/munchkin.jscookieFound: false, false, false, true, false

Tests whether the browser stops cookies from dpm.demdex.net from tracking users across websites.

passed: true, true, true, true, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://dpm.demdex.net/ibscookieFound: true, true, true, true, true

passed: trueurl: https://dpm.demdex.net/ibscookieFound: false

passed: true, true, true, true, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, false, false

passed: trueurl: https://dpm.demdex.net/ibscookieFound: false

passed: true, true, true, true, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://dpm.demdex.net/ibscookieFound: false, false, false, true, false

Tests whether the browser stops cookies from s.amazon-adsystem.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://s.amazon-adsystem.com/dcmcookieFound: true, true, true, true, true

passed: trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false

passed: true, true, true, true, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, false, false

passed: trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false

passed: true, true, true, true, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://s.amazon-adsystem.com/dcmcookieFound: false, false, false, true, false

Tests whether the browser stops cookies from ib.adnxs.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: true, true, true, true, true

passed: trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false

passed: false, false, false, false, falseurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: true, true, true, true, true

passed: true, true, true, true, trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false, false, false, false, false

passed: trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false

passed: true, true, true, true, trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://ib.adnxs.com/px?id=178248&t=1cookieFound: false, false, false, true, false

Tests whether the browser stops cookies from bat.bing.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://bat.bing.com/bat.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://bat.bing.com/bat.jscookieFound: true, true, true, true, true

passed: trueurl: https://bat.bing.com/bat.jscookieFound: false

passed: false, false, false, false, falseurl: https://bat.bing.com/bat.jscookieFound: true, true, true, true, true

passed: true, true, true, true, trueurl: https://bat.bing.com/bat.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://bat.bing.com/bat.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://bat.bing.com/bat.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://bat.bing.com/bat.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://bat.bing.com/bat.jscookieFound: false, false, false, false, false

passed: trueurl: https://bat.bing.com/bat.jscookieFound: false

passed: true, true, true, true, trueurl: https://bat.bing.com/bat.jscookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://bat.bing.com/bat.jscookieFound: false, false, false, true, false

Tests whether the browser stops cookies from static.chartbeat.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: true, true, true, true, true

passed: trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false

passed: false, false, false, false, falseurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: true, true, true, true, true

passed: true, true, true, true, trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false, false, false, false, false

passed: trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false

passed: true, true, true, true, trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://static.chartbeat.com/js/chartbeat.jscookieFound: false, false, false, true, false

Tests whether the browser stops cookies from dis.criteo.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: true, true, true, true, true

passed: trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false

passed: true, true, true, true, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, false, false

passed: trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false

passed: true, true, true, true, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspxcookieFound: false, false, false, true, false

Tests whether the browser stops cookies from securepubads.g.doubleclick.net from tracking users across websites.

passed: true, true, true, true, trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: true, true, true, true, true

passed: trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false

passed: true, true, true, true, trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false, false, false, false, false

passed: trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false

passed: true, true, true, true, trueurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://securepubads.g.doubleclick.net/static/glade.jscookieFound: true, true, true, true, true

Tests whether the browser stops cookies from connect.facebook.net from tracking users across websites.

passed: true, true, true, true, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: true, true, true, true, true

passed: trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false

passed: true, true, true, true, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, false, false, false, false

passed: trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false

passed: true, true, true, true, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, false, false, false, false

passed: true, false, true, false, trueurl: https://connect.facebook.net/en_US/fbevents.jscookieFound: false, true, false, true, false

Tests whether the browser stops cookies from www.google.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://www.google.com/pagead/1p-user-list/cookieFound: true, true, true, true, true

passed: trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false

passed: true, true, true, true, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, false, false

passed: trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false

passed: true, true, true, true, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://www.google.com/pagead/1p-user-list/cookieFound: false, false, false, true, false

Tests whether the browser stops cookies from google-analytics.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://google-analytics.com/urchin.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://google-analytics.com/urchin.jscookieFound: true, true, true, true, true

passed: trueurl: https://google-analytics.com/urchin.jscookieFound: false

passed: false, false, false, false, falseurl: https://google-analytics.com/urchin.jscookieFound: true, true, true, true, true

passed: true, true, true, true, trueurl: https://google-analytics.com/urchin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://google-analytics.com/urchin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://google-analytics.com/urchin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://google-analytics.com/urchin.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://google-analytics.com/urchin.jscookieFound: false, false, false, false, false

passed: trueurl: https://google-analytics.com/urchin.jscookieFound: false

passed: true, true, true, true, trueurl: https://google-analytics.com/urchin.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://google-analytics.com/urchin.jscookieFound: true, true, true, true, true

Tests whether the browser stops cookies from www.googletagmanager.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: true, true, true, true, true

passed: trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false

passed: false, false, false, false, falseurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: true, true, true, true, true

passed: true, true, true, true, trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false, false, false, false, false

passed: trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false

passed: true, true, true, true, trueurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZLcookieFound: true, true, true, true, true

Tests whether the browser stops cookies from dsum-sec.casalemedia.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: true, true, true, true, true

passed: trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false

passed: true, true, true, true, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, false, false

passed: trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false

passed: true, true, true, true, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1cookieFound: false, false, false, true, false

Tests whether the browser stops cookies from js-agent.newrelic.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: true, true, true, true, true

passed: trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false

passed: false, false, false, false, falseurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: true, true, true, true, true

passed: true, true, true, true, trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false, false, false, false, false

passed: trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false

passed: true, true, true, true, trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://js-agent.newrelic.com/nr-1212.min.jscookieFound: false, false, false, true, false

Tests whether the browser stops cookies from pixel.quantserve.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://pixel.quantserve.com/pixelcookieFound: true, true, true, true, true

passed: trueurl: https://pixel.quantserve.com/pixelcookieFound: false

passed: true, true, true, true, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, false, false

passed: trueurl: https://pixel.quantserve.com/pixelcookieFound: false

passed: true, true, true, true, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://pixel.quantserve.com/pixelcookieFound: false, false, false, true, false

Tests whether the browser stops cookies from sb.scorecardresearch.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: true, true, true, true, true

passed: trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false

passed: false, false, false, false, falseurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: true, true, true, true, true

passed: true, true, true, true, trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false, false, false, false, false

passed: trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false

passed: true, true, true, true, trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://sb.scorecardresearch.com/internal-c2/default/cs.jscookieFound: false, false, false, true, false

Tests whether the browser stops cookies from trc.taboola.com from tracking users across websites.

passed: true, true, true, true, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: true, true, true, true, true

passed: trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false

passed: true, true, true, true, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, false, false

passed: trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false

passed: true, true, true, true, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://trc.taboola.com/futureplc-tomsguide/trc/3/jsoncookieFound: false, false, false, true, false

Tests whether the browser stops cookies from t.co from tracking users across websites.

passed: true, true, true, true, trueurl: https://t.co/i/adsctcookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://t.co/i/adsctcookieFound: true, true, true, true, true

passed: trueurl: https://t.co/i/adsctcookieFound: false

passed: false, false, false, false, falseurl: https://t.co/i/adsctcookieFound: true, true, true, true, true

passed: true, true, true, true, trueurl: https://t.co/i/adsctcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://t.co/i/adsctcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://t.co/i/adsctcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://t.co/i/adsctcookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://t.co/i/adsctcookieFound: false, false, false, false, false

passed: trueurl: https://t.co/i/adsctcookieFound: false

passed: true, true, true, true, trueurl: https://t.co/i/adsctcookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://t.co/i/adsctcookieFound: false, false, false, true, false

Tests whether the browser stops cookies from yandex.ru from tracking users across websites.

passed: true, true, true, true, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, false, false

passed: false, false, false, false, falseurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: true, true, true, true, true

passed: trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false

passed: true, true, true, true, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, false, false

passed: true, true, true, true, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, false, false

passed: trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false

passed: true, true, true, true, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, false, false

passed: true, true, true, false, trueurl: https://yandex.ru/ads/system/header-bidding.jscookieFound: false, false, false, true, false

Alt-Svc allows the server to indicate to the web browser that a resource should be loaded on a different server. Because this is a persistent setting, it could be used to track users across websites if it is not correctly partitioned.

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h2result, different session: h3, h3, h3, h3, h2unsupported: false, false, false, false, truepassed: false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3result, different session: h2unsupported: falsepassed: truetest failed: false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h2, h3, h2, h3, h2result, different session: h3, h2, h3, h2, h3unsupported: true, false, true, false, truepassed: , true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h2result, different session: h2unsupported: truepassed: undefinedtest failed: false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The Cache API is a content storage mechanism originally introduced to support ServiceWorkers. If the same Cache object is accessible to multiple websites, it can be abused to track users.

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p,dad47994-1478-4269-bc67-9d5be7279695_1p,a224b08b-56ca-430a-8291-a1391ce3f527_1p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1presult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p,dad47994-1478-4269-bc67-9d5be7279695_1p,a224b08b-56ca-430a-8291-a1391ce3f527_1p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p,9e792e5f-2682-45df-a4b6-9926c1368572_1p,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p,be33e986-4227-4dad-98ab-849158191238_1p,d1bff213-a9f5-41c3-a065-c8b074cff472_1presult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p,9e792e5f-2682-45df-a4b6-9926c1368572_1p,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p,be33e986-4227-4dad-98ab-849158191238_1p,d1bff213-a9f5-41c3-a065-c8b074cff472_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_1presult, different session: Error: undefined is not an object (evaluating 'cacheKeys[0].url')unsupported: falsepassed: truetest failed: false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_1p,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p,6a79070f-7300-4f0a-b3e4-67db8452282d_1p,fc4e16e7-ac2e-48a9-8623-332158912d29_1p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1presult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_1p,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p,6a79070f-7300-4f0a-b3e4-67db8452282d_1p,fc4e16e7-ac2e-48a9-8623-332158912d29_1p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p,3c6d0906-4d80-439c-9124-ff2647fc503f_1p,29934d34-345f-4b44-91a5-4cfc4705276b_1p,c261a896-1dbf-455d-8a32-c51b15883279_1p,4befec68-5b8d-4639-b156-03db7501a173_1presult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p,3c6d0906-4d80-439c-9124-ff2647fc503f_1p,29934d34-345f-4b44-91a5-4cfc4705276b_1p,c261a896-1dbf-455d-8a32-c51b15883279_1p,4befec68-5b8d-4639-b156-03db7501a173_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:15e21312-33db-4994-b766-baad8032803f_1p,7ccbfb90-229d-427c-9f22-79caffc2fec3_1p,ab247bb9-7408-43c0-81f4-22f7335617f7_1p,1cc5af75-9209-4c31-a70b-5f98374d6544_1p,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_1presult, different session:Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:e64ec357-7007-4dab-a6fa-6650afbb1b92_1p,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56_1p,f2c54d89-4429-43be-9044-840a1c275e7f_1p,91894484-f7cc-4015-ae96-635239333863_1p,d4713458-e4ff-458e-b8a8-0a3562d0441b_1presult, different session:Error: cacheKeys[0] is undefined,Error: cacheKeys[0] is undefined,Error: cacheKeys[0] is undefined,Error: cacheKeys[0] is undefined,Error: cacheKeys[0] is undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p,299e3cd4-7953-4f77-801f-8985b822ac24_1p,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p,d31fb840-54e6-4419-b2ca-f532e60327ac_1p,8003e0ac-cbd3-4236-932f-a79792d54b62_1presult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p,299e3cd4-7953-4f77-801f-8985b822ac24_1p,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p,d31fb840-54e6-4419-b2ca-f532e60327ac_1punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_1p,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_1p,3ac91718-3eba-45e8-aceb-765d0391821b_1p,f2d6741d-a215-4cac-a81a-dec44031672d_1p,576d3332-f9c6-455d-bddd-b3b643b6c552_1presult, different session:Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url')unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81_1presult, different session: Error: cacheKeys[0] is undefinedunsupported: falsepassed: truetest failed: false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:24441439-f1db-4c84-bc96-50682c4e643e_1p,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p,e198d1f6-c1a6-4343-9907-302129e685e7_1p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1presult, different session:24441439-f1db-4c84-bc96-50682c4e643e_1p,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p,e198d1f6-c1a6-4343-9907-302129e685e7_1p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p,e74254c5-9034-45cd-b7ba-b7db726e55ab_1presult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p,e74254c5-9034-45cd-b7ba-b7db726e55ab_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p_http,dad47994-1478-4269-bc67-9d5be7279695_1p_http,a224b08b-56ca-430a-8291-a1391ce3f527_1p_http,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p_http,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1p_httpresult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p_http,dad47994-1478-4269-bc67-9d5be7279695_1p_http,a224b08b-56ca-430a-8291-a1391ce3f527_1p_http,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p_http,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p_http,9e792e5f-2682-45df-a4b6-9926c1368572_1p_http,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p_http,be33e986-4227-4dad-98ab-849158191238_1p_http,d1bff213-a9f5-41c3-a065-c8b074cff472_1p_httpresult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p_http,9e792e5f-2682-45df-a4b6-9926c1368572_1p_http,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p_http,be33e986-4227-4dad-98ab-849158191238_1p_http,d1bff213-a9f5-41c3-a065-c8b074cff472_1p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_1p_httpresult, different session: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_1p_httpunsupported: falsepassed: falsetest failed: false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_1p_http,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p_http,6a79070f-7300-4f0a-b3e4-67db8452282d_1p_http,fc4e16e7-ac2e-48a9-8623-332158912d29_1p_http,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1p_httpresult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_1p_http,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p_http,6a79070f-7300-4f0a-b3e4-67db8452282d_1p_http,fc4e16e7-ac2e-48a9-8623-332158912d29_1p_http,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p_http,3c6d0906-4d80-439c-9124-ff2647fc503f_1p_http,29934d34-345f-4b44-91a5-4cfc4705276b_1p_http,c261a896-1dbf-455d-8a32-c51b15883279_1p_http,4befec68-5b8d-4639-b156-03db7501a173_1p_httpresult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p_http,3c6d0906-4d80-439c-9124-ff2647fc503f_1p_http,29934d34-345f-4b44-91a5-4cfc4705276b_1p_http,c261a896-1dbf-455d-8a32-c51b15883279_1p_http,4befec68-5b8d-4639-b156-03db7501a173_1p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:15e21312-33db-4994-b766-baad8032803f_1p_http,7ccbfb90-229d-427c-9f22-79caffc2fec3_1p_http,ab247bb9-7408-43c0-81f4-22f7335617f7_1p_http,1cc5af75-9209-4c31-a70b-5f98374d6544_1p_http,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_1p_httpresult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:e64ec357-7007-4dab-a6fa-6650afbb1b92_1p_http,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56_1p_http,f2c54d89-4429-43be-9044-840a1c275e7f_1p_http,91894484-f7cc-4015-ae96-635239333863_1p_http,d4713458-e4ff-458e-b8a8-0a3562d0441b_1p_httpresult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p_http,299e3cd4-7953-4f77-801f-8985b822ac24_1p_http,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p_http,d31fb840-54e6-4419-b2ca-f532e60327ac_1p_http,8003e0ac-cbd3-4236-932f-a79792d54b62_1p_httpresult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p_http,299e3cd4-7953-4f77-801f-8985b822ac24_1p_http,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p_http,d31fb840-54e6-4419-b2ca-f532e60327ac_1p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_1p_http,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_1p_http,3ac91718-3eba-45e8-aceb-765d0391821b_1p_http,f2d6741d-a215-4cac-a81a-dec44031672d_1p_http,576d3332-f9c6-455d-bddd-b3b643b6c552_1p_httpresult, different session:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_1p_http,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_1p_http,3ac91718-3eba-45e8-aceb-765d0391821b_1p_http,f2d6741d-a215-4cac-a81a-dec44031672d_1p_http,576d3332-f9c6-455d-bddd-b3b643b6c552_1p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81_1p_httpresult, different session: nullunsupported: falsepassed: truetest failed: false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:24441439-f1db-4c84-bc96-50682c4e643e_1p_http,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p_http,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p_http,e198d1f6-c1a6-4343-9907-302129e685e7_1p_http,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1p_httpresult, different session:24441439-f1db-4c84-bc96-50682c4e643e_1p_http,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p_http,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p_http,e198d1f6-c1a6-4343-9907-302129e685e7_1p_http,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p_http,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p_http,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p_http,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p_http,e74254c5-9034-45cd-b7ba-b7db726e55ab_1p_httpresult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p_http,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p_http,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p_http,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p_http,e74254c5-9034-45cd-b7ba-b7db726e55ab_1p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p_js,dad47994-1478-4269-bc67-9d5be7279695_1p_js,a224b08b-56ca-430a-8291-a1391ce3f527_1p_js,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p_js,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1p_jsresult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p_js,dad47994-1478-4269-bc67-9d5be7279695_1p_js,a224b08b-56ca-430a-8291-a1391ce3f527_1p_js,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p_js,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p_js,9e792e5f-2682-45df-a4b6-9926c1368572_1p_js,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p_js,be33e986-4227-4dad-98ab-849158191238_1p_js,d1bff213-a9f5-41c3-a065-c8b074cff472_1p_jsresult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p_js,9e792e5f-2682-45df-a4b6-9926c1368572_1p_js,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p_js,be33e986-4227-4dad-98ab-849158191238_1p_js,d1bff213-a9f5-41c3-a065-c8b074cff472_1p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_1p_jsresult, different session: nullunsupported: falsepassed: truetest failed: false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:026115d8-5ec8-4705-b68d-299ea05d729f_1p_js,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p_js,6a79070f-7300-4f0a-b3e4-67db8452282d_1p_js,fc4e16e7-ac2e-48a9-8623-332158912d29_1p_js,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1p_jsresult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_1p_js,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p_js,6a79070f-7300-4f0a-b3e4-67db8452282d_1p_js,fc4e16e7-ac2e-48a9-8623-332158912d29_1p_js,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p_js,3c6d0906-4d80-439c-9124-ff2647fc503f_1p_js,29934d34-345f-4b44-91a5-4cfc4705276b_1p_js,c261a896-1dbf-455d-8a32-c51b15883279_1p_js,4befec68-5b8d-4639-b156-03db7501a173_1p_jsresult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p_js,3c6d0906-4d80-439c-9124-ff2647fc503f_1p_js,29934d34-345f-4b44-91a5-4cfc4705276b_1p_js,c261a896-1dbf-455d-8a32-c51b15883279_1p_js,4befec68-5b8d-4639-b156-03db7501a173_1p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:15e21312-33db-4994-b766-baad8032803f_1p_js,7ccbfb90-229d-427c-9f22-79caffc2fec3_1p_js,ab247bb9-7408-43c0-81f4-22f7335617f7_1p_js,1cc5af75-9209-4c31-a70b-5f98374d6544_1p_js,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_1p_jsresult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:e64ec357-7007-4dab-a6fa-6650afbb1b92_1p_js,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56_1p_js,f2c54d89-4429-43be-9044-840a1c275e7f_1p_js,91894484-f7cc-4015-ae96-635239333863_1p_js,d4713458-e4ff-458e-b8a8-0a3562d0441b_1p_jsresult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p_js,299e3cd4-7953-4f77-801f-8985b822ac24_1p_js,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p_js,d31fb840-54e6-4419-b2ca-f532e60327ac_1p_js,8003e0ac-cbd3-4236-932f-a79792d54b62_1p_jsresult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p_js,299e3cd4-7953-4f77-801f-8985b822ac24_1p_js,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p_js,d31fb840-54e6-4419-b2ca-f532e60327ac_1p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_1p_js,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_1p_js,3ac91718-3eba-45e8-aceb-765d0391821b_1p_js,f2d6741d-a215-4cac-a81a-dec44031672d_1p_js,576d3332-f9c6-455d-bddd-b3b643b6c552_1p_jsresult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81_1p_jsresult, different session: nullunsupported: falsepassed: truetest failed: false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:24441439-f1db-4c84-bc96-50682c4e643e_1p_js,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p_js,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p_js,e198d1f6-c1a6-4343-9907-302129e685e7_1p_js,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1p_jsresult, different session:24441439-f1db-4c84-bc96-50682c4e643e_1p_js,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p_js,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p_js,e198d1f6-c1a6-4343-9907-302129e685e7_1p_js,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p_js,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p_js,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p_js,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p_js,e74254c5-9034-45cd-b7ba-b7db726e55ab_1p_jsresult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p_js,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p_js,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p_js,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p_js,e74254c5-9034-45cd-b7ba-b7db726e55ab_1p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p,dad47994-1478-4269-bc67-9d5be7279695_1p,a224b08b-56ca-430a-8291-a1391ce3f527_1p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1presult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p,dad47994-1478-4269-bc67-9d5be7279695_1p,a224b08b-56ca-430a-8291-a1391ce3f527_1p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p,9e792e5f-2682-45df-a4b6-9926c1368572_1p,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p,be33e986-4227-4dad-98ab-849158191238_1p,d1bff213-a9f5-41c3-a065-c8b074cff472_1presult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p,9e792e5f-2682-45df-a4b6-9926c1368572_1p,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p,be33e986-4227-4dad-98ab-849158191238_1p,d1bff213-a9f5-41c3-a065-c8b074cff472_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_1presult, different session: nullunsupported: falsepassed: truetest failed: false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_1p,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p,6a79070f-7300-4f0a-b3e4-67db8452282d_1p,fc4e16e7-ac2e-48a9-8623-332158912d29_1p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1presult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_1p,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p,6a79070f-7300-4f0a-b3e4-67db8452282d_1p,fc4e16e7-ac2e-48a9-8623-332158912d29_1p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p,3c6d0906-4d80-439c-9124-ff2647fc503f_1p,29934d34-345f-4b44-91a5-4cfc4705276b_1p,c261a896-1dbf-455d-8a32-c51b15883279_1p,4befec68-5b8d-4639-b156-03db7501a173_1presult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p,3c6d0906-4d80-439c-9124-ff2647fc503f_1p,29934d34-345f-4b44-91a5-4cfc4705276b_1p,c261a896-1dbf-455d-8a32-c51b15883279_1p,4befec68-5b8d-4639-b156-03db7501a173_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:15e21312-33db-4994-b766-baad8032803f_1p,7ccbfb90-229d-427c-9f22-79caffc2fec3_1p,ab247bb9-7408-43c0-81f4-22f7335617f7_1p,1cc5af75-9209-4c31-a70b-5f98374d6544_1p,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_1presult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedresult, different session:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p,299e3cd4-7953-4f77-801f-8985b822ac24_1p,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p,d31fb840-54e6-4419-b2ca-f532e60327ac_1p,8003e0ac-cbd3-4236-932f-a79792d54b62_1presult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p,299e3cd4-7953-4f77-801f-8985b822ac24_1p,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p,d31fb840-54e6-4419-b2ca-f532e60327ac_1punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_1p,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_1p,3ac91718-3eba-45e8-aceb-765d0391821b_1p,f2d6741d-a215-4cac-a81a-dec44031672d_1p,576d3332-f9c6-455d-bddd-b3b643b6c552_1presult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session: Error: Unsupportedresult, different session: Error: Unsupportedunsupported: truepassed: undefinedtest failed: false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:24441439-f1db-4c84-bc96-50682c4e643e_1p,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p,e198d1f6-c1a6-4343-9907-302129e685e7_1p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1presult, different session:24441439-f1db-4c84-bc96-50682c4e643e_1p,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p,e198d1f6-c1a6-4343-9907-302129e685e7_1p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p,e74254c5-9034-45cd-b7ba-b7db726e55ab_1presult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p,e74254c5-9034-45cd-b7ba-b7db726e55ab_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_8374573836196648,fake_5016942596411968,fake_6784739984412274,fake_38345485058313034,fake_7151269335732582result, different session:fake_8374573836196648,fake_5016942596411968,fake_6784739984412274,fake_38345485058313034,fake_7151269335732582unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_9421639164602122,fake_907481416303692,fake_42188752684724506,fake_5432043583587878,fake_6281708663136449result, different session:fake_9421639164602122,fake_907481416303692,fake_42188752684724506,fake_5432043583587878,fake_6281708663136449unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session: fake_5875437069239351result, different session: fake_5875437069239351unsupported: falsepassed: falsetest failed: false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_2643973676589473,fake_022225868321188447,fake_8301322471296209,fake_5174988960123137,fake_2208258862241399result, different session:fake_2643973676589473,fake_022225868321188447,fake_8301322471296209,fake_5174988960123137,fake_2208258862241399unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_13049738510348785,fake_28643035053366006,fake_957166489114246,fake_40982588970736744,fake_9999324651115138result, different session:fake_13049738510348785,fake_28643035053366006,fake_957166489114246,fake_40982588970736744,fake_9999324651115138unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_6468005961586814,fake_10364011661332762,fake_3557616170571203,fake_4231429633729431,fake_5439474468284871result, different session:fake_8600066108816626,fake_3878889142263855,fake_7683058449357174,fake_5678257756738119,fake_9816724461831916unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_27956785001787443,fake_004293230001254811,fake_6250720038175175,fake_7932107424156387,fake_02103708503003654result, different session:fake_5539170501446418,fake_3704247022660161,fake_7621112560117687,fake_6709169175804159,fake_9532987596431919unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_5727665523781669,fake_9057502806229576,fake_3498195461895546,fake_46541733946750474,fake_9879200972691369result, different session:fake_5727665523781669,fake_9057502806229576,fake_3498195461895546,fake_46541733946750474,8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_7244423455055082,fake_24212930874319127,fake_035754621544405785,fake_636814728326752,fake_025012070084092564result, different session:fake_7244423455055082,fake_24212930874319127,fake_035754621544405785,fake_636814728326752,fake_025012070084092564unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session: fake_6656581615126533result, different session: fake_7038113513629438unsupported: falsepassed: truetest failed: false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_29033556591442466,fake_44710162939940634,fake_24506211236560027,fake_3844722749724192,fake_04512541041620688result, different session:fake_29033556591442466,fake_44710162939940634,fake_24506211236560027,fake_3844722749724192,fake_04512541041620688unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_46403955064137303,fake_7840842773282881,fake_3532735683692636,fake_8450249916357031,fake_7215788472205031result, different session:fake_46403955064137303,fake_7840842773282881,fake_3532735683692636,fake_8450249916357031,fake_7215788472205031unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 2, 2, 2, 2, 2result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

When a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

An iframe is an element in a web page than allows websites to embed a second web page. Caching of this web page could be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Caching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p,dad47994-1478-4269-bc67-9d5be7279695_1p,a224b08b-56ca-430a-8291-a1391ce3f527_1p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1presult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p,dad47994-1478-4269-bc67-9d5be7279695_1p,a224b08b-56ca-430a-8291-a1391ce3f527_1p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p,9e792e5f-2682-45df-a4b6-9926c1368572_1p,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p,be33e986-4227-4dad-98ab-849158191238_1p,d1bff213-a9f5-41c3-a065-c8b074cff472_1presult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p,9e792e5f-2682-45df-a4b6-9926c1368572_1p,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p,be33e986-4227-4dad-98ab-849158191238_1p,d1bff213-a9f5-41c3-a065-c8b074cff472_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_1presult, different session: undefinedunsupported: falsepassed: truetest failed: false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_1p,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p,6a79070f-7300-4f0a-b3e4-67db8452282d_1p,fc4e16e7-ac2e-48a9-8623-332158912d29_1p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1presult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_1p,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p,6a79070f-7300-4f0a-b3e4-67db8452282d_1p,fc4e16e7-ac2e-48a9-8623-332158912d29_1p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p,3c6d0906-4d80-439c-9124-ff2647fc503f_1p,29934d34-345f-4b44-91a5-4cfc4705276b_1p,c261a896-1dbf-455d-8a32-c51b15883279_1p,4befec68-5b8d-4639-b156-03db7501a173_1presult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p,3c6d0906-4d80-439c-9124-ff2647fc503f_1p,29934d34-345f-4b44-91a5-4cfc4705276b_1p,c261a896-1dbf-455d-8a32-c51b15883279_1p,4befec68-5b8d-4639-b156-03db7501a173_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:15e21312-33db-4994-b766-baad8032803f_1p,7ccbfb90-229d-427c-9f22-79caffc2fec3_1p,ab247bb9-7408-43c0-81f4-22f7335617f7_1p,1cc5af75-9209-4c31-a70b-5f98374d6544_1p,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_1presult, different session: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:e64ec357-7007-4dab-a6fa-6650afbb1b92_1p,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56_1p,f2c54d89-4429-43be-9044-840a1c275e7f_1p,91894484-f7cc-4015-ae96-635239333863_1p,d4713458-e4ff-458e-b8a8-0a3562d0441b_1presult, different session: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p,299e3cd4-7953-4f77-801f-8985b822ac24_1p,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p,d31fb840-54e6-4419-b2ca-f532e60327ac_1p,8003e0ac-cbd3-4236-932f-a79792d54b62_1presult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p,299e3cd4-7953-4f77-801f-8985b822ac24_1p,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p,d31fb840-54e6-4419-b2ca-f532e60327ac_1punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_1p,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_1p,3ac91718-3eba-45e8-aceb-765d0391821b_1p,f2d6741d-a215-4cac-a81a-dec44031672d_1p,576d3332-f9c6-455d-bddd-b3b643b6c552_1presult, different session: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81_1presult, different session: undefinedunsupported: falsepassed: truetest failed: false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:24441439-f1db-4c84-bc96-50682c4e643e_1p,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p,e198d1f6-c1a6-4343-9907-302129e685e7_1p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1presult, different session:24441439-f1db-4c84-bc96-50682c4e643e_1p,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p,e198d1f6-c1a6-4343-9907-302129e685e7_1p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p,e74254c5-9034-45cd-b7ba-b7db726e55ab_1presult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p,e74254c5-9034-45cd-b7ba-b7db726e55ab_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p,dad47994-1478-4269-bc67-9d5be7279695_1p,a224b08b-56ca-430a-8291-a1391ce3f527_1p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1presult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_1p,dad47994-1478-4269-bc67-9d5be7279695_1p,a224b08b-56ca-430a-8291-a1391ce3f527_1p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_1p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p,9e792e5f-2682-45df-a4b6-9926c1368572_1p,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p,be33e986-4227-4dad-98ab-849158191238_1p,d1bff213-a9f5-41c3-a065-c8b074cff472_1presult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_1p,9e792e5f-2682-45df-a4b6-9926c1368572_1p,96cb1992-e972-4aef-8062-ef9c5ed16a01_1p,be33e986-4227-4dad-98ab-849158191238_1p,d1bff213-a9f5-41c3-a065-c8b074cff472_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session: fb5e2f4c-c5b5-411f-a3b3-03e08b0cc599_1presult, different session: nullunsupported: falsepassed: truetest failed: false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_1p,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p,6a79070f-7300-4f0a-b3e4-67db8452282d_1p,fc4e16e7-ac2e-48a9-8623-332158912d29_1p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1presult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_1p,b33c419d-acf6-4795-95e0-d5d753f2f16d_1p,6a79070f-7300-4f0a-b3e4-67db8452282d_1p,fc4e16e7-ac2e-48a9-8623-332158912d29_1p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p,3c6d0906-4d80-439c-9124-ff2647fc503f_1p,29934d34-345f-4b44-91a5-4cfc4705276b_1p,c261a896-1dbf-455d-8a32-c51b15883279_1p,4befec68-5b8d-4639-b156-03db7501a173_1presult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_1p,3c6d0906-4d80-439c-9124-ff2647fc503f_1p,29934d34-345f-4b44-91a5-4cfc4705276b_1p,c261a896-1dbf-455d-8a32-c51b15883279_1p,4befec68-5b8d-4639-b156-03db7501a173_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:15e21312-33db-4994-b766-baad8032803f_1p,7ccbfb90-229d-427c-9f22-79caffc2fec3_1p,ab247bb9-7408-43c0-81f4-22f7335617f7_1p,1cc5af75-9209-4c31-a70b-5f98374d6544_1p,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_1presult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:e64ec357-7007-4dab-a6fa-6650afbb1b92_1p,ea216c9a-9cb5-4630-8ddf-2d5bf0ab8b56_1p,f2c54d89-4429-43be-9044-840a1c275e7f_1p,91894484-f7cc-4015-ae96-635239333863_1p,d4713458-e4ff-458e-b8a8-0a3562d0441b_1presult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p,299e3cd4-7953-4f77-801f-8985b822ac24_1p,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p,d31fb840-54e6-4419-b2ca-f532e60327ac_1p,8003e0ac-cbd3-4236-932f-a79792d54b62_1presult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_1p,299e3cd4-7953-4f77-801f-8985b822ac24_1p,aad11fab-6660-48f9-b28d-4b2ee45a44df_1p,d31fb840-54e6-4419-b2ca-f532e60327ac_1punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:c0150e2b-e0d0-41b9-b45d-d902a1eb8b52_1p,fe4b6d38-97a5-47e0-8ce9-abd6b175891b_1p,3ac91718-3eba-45e8-aceb-765d0391821b_1p,f2d6741d-a215-4cac-a81a-dec44031672d_1p,576d3332-f9c6-455d-bddd-b3b643b6c552_1presult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session: 49fe77ef-a8ac-4213-90fb-9b81cb45fd81_1presult, different session: nullunsupported: falsepassed: truetest failed: false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:24441439-f1db-4c84-bc96-50682c4e643e_1p,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p,e198d1f6-c1a6-4343-9907-302129e685e7_1p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1presult, different session:24441439-f1db-4c84-bc96-50682c4e643e_1p,6d1c53c8-70cf-47eb-9a21-0ba706352479_1p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_1p,e198d1f6-c1a6-4343-9907-302129e685e7_1p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p,e74254c5-9034-45cd-b7ba-b7db726e55ab_1presult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_1p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_1p,32f534ec-f0c9-4fb9-a393-c743feebc30e_1p,085080b8-ac7e-4d13-b00e-fceb219d3dac_1p,e74254c5-9034-45cd-b7ba-b7db726e55ab_1punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: Error: No requests receivedresult, different session: Error: No requests receivedunsupported: truepassed: undefinedtest failed: false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: Error: No requests receivedresult, different session: Error: No requests receivedunsupported: truepassed: undefinedtest failed: false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Caching of scripts in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Alt-Svc allows the server to indicate to the web browser that a resource should be loaded on a different server. Because this is a persistent setting, it could be used to track users across websites if it is not correctly partitioned.

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h2result, different session: h3, h3, h3, h3, h2unsupported: false, false, false, false, truepassed: false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h2result, different session: h3unsupported: truepassed: undefinedtest failed: false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h2, h2, h2, h2, h2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h2unsupported: false, false, false, false, falsepassed: false, false, false, false, truetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h2, h2, h2, h2, h2result, different session: h2, h2, h2, h2, h2unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h2result, different session: h2unsupported: truepassed: undefinedtest failed: false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async () => {      // Clear Alt-Svc caching first.      let responseText = "";      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/clear");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after clear:", responseText);      // Store "h3" state in Alt-Svc cache      for (let i = 0; i < 3; ++i) {        await fetch(altSvcOrigin + "/set");        await sleepMs(100);      }      responseText = await fetchText(altSvcOrigin + "/protocol");      console.log("after set:", responseText);    }read: async () => {      const protocol = await fetchText(altSvcOrigin + "/protocol");      if ((new URL(location)).searchParams.get("thirdparty") === "same") {        if (protocol !== "h3") {          throw new Error("Unsupported");        }      }      return protocol;    }result, same session: h3, h3, h3, h3, h3result, different session: h3, h3, h3, h3, h3unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The Cache API is a content storage mechanism originally introduced to support ServiceWorkers. If the same Cache object is accessible to multiple websites, it can be abused to track users.

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p,dad47994-1478-4269-bc67-9d5be7279695_3p,a224b08b-56ca-430a-8291-a1391ce3f527_3p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3presult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p,dad47994-1478-4269-bc67-9d5be7279695_3p,a224b08b-56ca-430a-8291-a1391ce3f527_3p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p,9e792e5f-2682-45df-a4b6-9926c1368572_3p,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p,be33e986-4227-4dad-98ab-849158191238_3p,d1bff213-a9f5-41c3-a065-c8b074cff472_3presult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p,9e792e5f-2682-45df-a4b6-9926c1368572_3p,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p,be33e986-4227-4dad-98ab-849158191238_3p,d1bff213-a9f5-41c3-a065-c8b074cff472_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session: Error: undefined is not an object (evaluating 'cacheKeys[0].url')result, different session: Error: undefined is not an object (evaluating 'cacheKeys[0].url')unsupported: truepassed: undefinedtest failed: false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_3p,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p,6a79070f-7300-4f0a-b3e4-67db8452282d_3p,fc4e16e7-ac2e-48a9-8623-332158912d29_3p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3presult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_3p,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p,6a79070f-7300-4f0a-b3e4-67db8452282d_3p,fc4e16e7-ac2e-48a9-8623-332158912d29_3p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p,3c6d0906-4d80-439c-9124-ff2647fc503f_3p,29934d34-345f-4b44-91a5-4cfc4705276b_3p,c261a896-1dbf-455d-8a32-c51b15883279_3p,4befec68-5b8d-4639-b156-03db7501a173_3presult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p,3c6d0906-4d80-439c-9124-ff2647fc503f_3p,29934d34-345f-4b44-91a5-4cfc4705276b_3p,c261a896-1dbf-455d-8a32-c51b15883279_3p,4befec68-5b8d-4639-b156-03db7501a173_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:15e21312-33db-4994-b766-baad8032803f_3p,7ccbfb90-229d-427c-9f22-79caffc2fec3_3p,ab247bb9-7408-43c0-81f4-22f7335617f7_3p,1cc5af75-9209-4c31-a70b-5f98374d6544_3p,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_3presult, different session:Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefined,Error: can't access property "url",cacheKeys[0] is undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.result, different session:Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p,299e3cd4-7953-4f77-801f-8985b822ac24_3p,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p,d31fb840-54e6-4419-b2ca-f532e60327ac_3p,8003e0ac-cbd3-4236-932f-a79792d54b62_3presult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p,299e3cd4-7953-4f77-801f-8985b822ac24_3p,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p,d31fb840-54e6-4419-b2ca-f532e60327ac_3p,8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:Error: undefined is not an object (evaluating 'cacheKeys[0].url'),fe4b6d38-97a5-47e0-8ce9-abd6b175891b_3p,Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),576d3332-f9c6-455d-bddd-b3b643b6c552_3presult, different session:Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url'),Error: undefined is not an object (evaluating 'cacheKeys[0].url')unsupported: true, false, true, true, falsepassed: , true, truetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session: Error: The operation is insecure.result, different session: Error: The operation is insecure.unsupported: truepassed: undefinedtest failed: false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:24441439-f1db-4c84-bc96-50682c4e643e_3p,6d1c53c8-70cf-47eb-9a21-0ba706352479_3p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_3p,e198d1f6-c1a6-4343-9907-302129e685e7_3p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_3presult, different session:24441439-f1db-4c84-bc96-50682c4e643e_3p,6d1c53c8-70cf-47eb-9a21-0ba706352479_3p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_3p,e198d1f6-c1a6-4343-9907-302129e685e7_3p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      try {        let cache = await caches.open("supercookies");        cache.addAll([`test.css?key=${key}`]);      } catch (e) {        throw new Error("Unsupported");      }    }read: async () => {      let cache = await caches.open("supercookies");      let cacheKeys = await cache.keys();      let url = cacheKeys[0].url;      return (new URL(url)).searchParams.get("key");    }result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p,e74254c5-9034-45cd-b7ba-b7db726e55ab_3presult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p,e74254c5-9034-45cd-b7ba-b7db726e55ab_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p_http,dad47994-1478-4269-bc67-9d5be7279695_3p_http,a224b08b-56ca-430a-8291-a1391ce3f527_3p_http,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p_http,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3p_httpresult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p_http,9e792e5f-2682-45df-a4b6-9926c1368572_3p_http,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p_http,be33e986-4227-4dad-98ab-849158191238_3p_http,d1bff213-a9f5-41c3-a065-c8b074cff472_3p_httpresult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p_http,9e792e5f-2682-45df-a4b6-9926c1368572_3p_http,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p_http,be33e986-4227-4dad-98ab-849158191238_3p_http,d1bff213-a9f5-41c3-a065-c8b074cff472_3p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session: nullresult, different session: nullunsupported: truepassed: undefinedtest failed: false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_3p_http,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p_http,6a79070f-7300-4f0a-b3e4-67db8452282d_3p_http,fc4e16e7-ac2e-48a9-8623-332158912d29_3p_http,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3p_httpresult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_3p_http,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p_http,6a79070f-7300-4f0a-b3e4-67db8452282d_3p_http,fc4e16e7-ac2e-48a9-8623-332158912d29_3p_http,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p_http,3c6d0906-4d80-439c-9124-ff2647fc503f_3p_http,29934d34-345f-4b44-91a5-4cfc4705276b_3p_http,c261a896-1dbf-455d-8a32-c51b15883279_3p_http,4befec68-5b8d-4639-b156-03db7501a173_3p_httpresult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p_http,3c6d0906-4d80-439c-9124-ff2647fc503f_3p_http,29934d34-345f-4b44-91a5-4cfc4705276b_3p_http,c261a896-1dbf-455d-8a32-c51b15883279_3p_http,4befec68-5b8d-4639-b156-03db7501a173_3p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p_http,299e3cd4-7953-4f77-801f-8985b822ac24_3p_http,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p_http,d31fb840-54e6-4419-b2ca-f532e60327ac_3p_http,8003e0ac-cbd3-4236-932f-a79792d54b62_3p_httpresult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p_http,299e3cd4-7953-4f77-801f-8985b822ac24_3p_http,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p_http,d31fb840-54e6-4419-b2ca-f532e60327ac_3p_http,8003e0ac-cbd3-4236-932f-a79792d54b62_3p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session: nullresult, different session: nullunsupported: truepassed: undefinedtest failed: false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (secret) => {      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.      await fetch(`${baseURI}cookie?secret=${secret}_http`);    }read: async () => {      // Test if we now send a requests with a 'cookie' header containing the secret.      let response = await fetch(`${baseURI}headers`);      let cookie = (await response.json())["cookie"];      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;    }result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p_http,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p_http,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p_http,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p_http,e74254c5-9034-45cd-b7ba-b7db726e55ab_3p_httpresult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p_http,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p_http,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p_http,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p_http,e74254c5-9034-45cd-b7ba-b7db726e55ab_3p_httpunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p_js,dad47994-1478-4269-bc67-9d5be7279695_3p_js,a224b08b-56ca-430a-8291-a1391ce3f527_3p_js,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p_js,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3p_jsresult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p_js,9e792e5f-2682-45df-a4b6-9926c1368572_3p_js,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p_js,be33e986-4227-4dad-98ab-849158191238_3p_js,d1bff213-a9f5-41c3-a065-c8b074cff472_3p_jsresult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p_js,9e792e5f-2682-45df-a4b6-9926c1368572_3p_js,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p_js,be33e986-4227-4dad-98ab-849158191238_3p_js,d1bff213-a9f5-41c3-a065-c8b074cff472_3p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session: nullresult, different session: nullunsupported: truepassed: undefinedtest failed: false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:026115d8-5ec8-4705-b68d-299ea05d729f_3p_js,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p_js,6a79070f-7300-4f0a-b3e4-67db8452282d_3p_js,fc4e16e7-ac2e-48a9-8623-332158912d29_3p_js,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3p_jsresult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_3p_js,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p_js,6a79070f-7300-4f0a-b3e4-67db8452282d_3p_js,fc4e16e7-ac2e-48a9-8623-332158912d29_3p_js,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p_js,3c6d0906-4d80-439c-9124-ff2647fc503f_3p_js,29934d34-345f-4b44-91a5-4cfc4705276b_3p_js,c261a896-1dbf-455d-8a32-c51b15883279_3p_js,4befec68-5b8d-4639-b156-03db7501a173_3p_jsresult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p_js,3c6d0906-4d80-439c-9124-ff2647fc503f_3p_js,29934d34-345f-4b44-91a5-4cfc4705276b_3p_js,c261a896-1dbf-455d-8a32-c51b15883279_3p_js,4befec68-5b8d-4639-b156-03db7501a173_3p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p_js,299e3cd4-7953-4f77-801f-8985b822ac24_3p_js,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p_js,d31fb840-54e6-4419-b2ca-f532e60327ac_3p_js,8003e0ac-cbd3-4236-932f-a79792d54b62_3p_jsresult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p_js,299e3cd4-7953-4f77-801f-8985b822ac24_3p_js,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p_js,d31fb840-54e6-4419-b2ca-f532e60327ac_3p_js,8003e0ac-cbd3-4236-932f-a79792d54b62_3p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session: nullresult, different session: nullunsupported: truepassed: undefinedtest failed: false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (secret) => {      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;    }read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : nullresult, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p_js,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p_js,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p_js,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p_js,e74254c5-9034-45cd-b7ba-b7db726e55ab_3p_jsresult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p_js,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p_js,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p_js,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p_js,e74254c5-9034-45cd-b7ba-b7db726e55ab_3p_jsunsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p,dad47994-1478-4269-bc67-9d5be7279695_3p,a224b08b-56ca-430a-8291-a1391ce3f527_3p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3presult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p,9e792e5f-2682-45df-a4b6-9926c1368572_3p,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p,be33e986-4227-4dad-98ab-849158191238_3p,d1bff213-a9f5-41c3-a065-c8b074cff472_3presult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p,9e792e5f-2682-45df-a4b6-9926c1368572_3p,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p,be33e986-4227-4dad-98ab-849158191238_3p,d1bff213-a9f5-41c3-a065-c8b074cff472_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session: Error: Type errorresult, different session: Error: Type errorunsupported: truepassed: undefinedtest failed: false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_3p,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p,6a79070f-7300-4f0a-b3e4-67db8452282d_3p,fc4e16e7-ac2e-48a9-8623-332158912d29_3p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3presult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_3p,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p,6a79070f-7300-4f0a-b3e4-67db8452282d_3p,fc4e16e7-ac2e-48a9-8623-332158912d29_3p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p,3c6d0906-4d80-439c-9124-ff2647fc503f_3p,29934d34-345f-4b44-91a5-4cfc4705276b_3p,c261a896-1dbf-455d-8a32-c51b15883279_3p,4befec68-5b8d-4639-b156-03db7501a173_3presult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p,3c6d0906-4d80-439c-9124-ff2647fc503f_3p,29934d34-345f-4b44-91a5-4cfc4705276b_3p,c261a896-1dbf-455d-8a32-c51b15883279_3p,4befec68-5b8d-4639-b156-03db7501a173_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedresult, different session:Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupportedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p,299e3cd4-7953-4f77-801f-8985b822ac24_3p,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p,d31fb840-54e6-4419-b2ca-f532e60327ac_3p,8003e0ac-cbd3-4236-932f-a79792d54b62_3presult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p,299e3cd4-7953-4f77-801f-8985b822ac24_3p,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p,d31fb840-54e6-4419-b2ca-f532e60327ac_3p,8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:Error: Type error,Error: Type error,Error: Type error,Error: Type error,Error: Type errorresult, different session:Error: Type error,Error: Type error,Error: Type error,Error: Type error,Error: Type errorunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session: Error: Unsupportedresult, different session: Error: Unsupportedunsupported: truepassed: undefinedtest failed: false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session: , , , ,result, different session: , , , ,unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (data) => {      const msPerHour = 60 * 60 * 1000;      if (!window.cookieStore) {        throw new Error("Unsupported");      }      window.cookieStore.set({        name: "partition_test",        value: data,        expires: Date.now() + msPerHour,        sameSite: "none"      });    }read: async () => {      if (!window.cookieStore) {        throw new Error("Unsupported");      }      const cookie = await window.cookieStore.get("partition_test");      if (!cookie) {        return null;      }      return cookie.value;    }result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p,e74254c5-9034-45cd-b7ba-b7db726e55ab_3presult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p,e74254c5-9034-45cd-b7ba-b7db726e55ab_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_4643382260063025,fake_18843478554280102,fake_2460702883411925,fake_5277880503392645,fake_6649850823794461result, different session:fake_4643382260063025,fake_18843478554280102,fake_2460702883411925,fake_5277880503392645,fake_6649850823794461unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_13818532558779562,fake_69139071572649,fake_04857852975198962,fake_44672334973174577,fake_7454596219238858result, different session:fake_13818532558779562,fake_69139071572649,fake_04857852975198962,fake_44672334973174577,fake_7454596219238858unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session: fake_5424813782842868result, different session: fake_5424813782842868unsupported: falsepassed: falsetest failed: false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_503611538179864,fake_996458281630414,fake_4691599446537664,fake_16968170168902552,fake_24681608680209388result, different session:fake_503611538179864,fake_996458281630414,fake_4691599446537664,fake_16968170168902552,fake_24681608680209388unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_9304468822662337,fake_07148612551107969,fake_24204856057461988,fake_651769401887335,fake_3807823238184016result, different session:fake_9304468822662337,fake_07148612551107969,fake_24204856057461988,fake_651769401887335,fake_3807823238184016unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_9233556792114279,fake_22991007411362552,fake_8508757663104101,fake_71907575168684,fake_052087309080739885result, different session:fake_6691155655854977,fake_1507158825664754,fake_7463189443032583,fake_1312769824328197,fake_31805385919950213unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_7952243052546557,fake_8209465416548625,fake_26573564261859506,fake_21927656846860888,fake_14672965978312358result, different session:fake_21027849808915788,fake_03325659841483497,fake_052067100602784855,fake_4618116442706619,fake_8331929166112997unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_1918511172485211,fake_048477323493428814,fake_06270514175285191,fake_36826897012900983,fake_1776890421306232result, different session:fake_1918511172485211,fake_048477323493428814,fake_06270514175285191,fake_36826897012900983,fake_1776890421306232unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_1602876405004816,fake_43380155287329725,fake_05017868160946781,fake_8395560956408143,fake_32811049793362157result, different session:fake_1602876405004816,fake_43380155287329725,fake_05017868160946781,fake_8395560956408143,fake_32811049793362157unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session: fake_1483501530818525result, different session: fake_586186540085248unsupported: falsepassed: truetest failed: false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_5894738129327872,fake_9982877997271009,fake_7770689457444975,fake_2874532567744983,fake_23745569455879223result, different session:fake_5894738129327872,fake_9982877997271009,fake_7770689457444975,fake_2874532567744983,fake_23745569455879223unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return key;    }read: async (key) => {      const href = testURI("resource", "css", key);      const head = document.getElementsByTagName("head")[0];      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;      const testElement = document.querySelector("#css");      let fontFamily;      while (true) {        await sleepMs(100);        fontFamily = getComputedStyle(testElement).fontFamily;        if (fontFamily.startsWith("fake")) {          break;        }      }      console.log(fontFamily);      return fontFamily;    }result, same session:fake_14299042030113074,fake_3181573801298443,fake_15626448445829455,fake_4567322865583332,fake_6639414872491132result, different session:fake_14299042030113074,fake_3181573801298443,fake_15626448445829455,fake_4567322865583332,fake_6639414872491132unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => keyread: async (key) => {      // Wait for the favicon to load (defined in supercookies.html)      await sleepMs(2000);      let response = await fetch(        testURI("ctr", "favicon", key), {"cache": "reload"});      let count = (await response.text()).trim();      if (count === "0") {        throw new Error("No requests received");      }      return count;    }result, same session: 2, 2, 2, 2, 2result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

When a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      return key;    }read: async (key) => {      let response = await fetch(testURI("resource", "fetch", key),                                 {cache: "force-cache"});      let countResponse = await fetch(testURI("ctr", "fetch", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      return key;    }read: async (key) => {      const text = document.createElement("span");      text.id = "text";      text.innerText = "test";      document.body.appendChild(text);      const originalWidth = text.getBoundingClientRect().width;      let style = document.createElement("style");      style.type='text/css';      let fontURI = testURI("resource", "font", key);      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;      document.getElementsByTagName("head")[0].appendChild(style);      let newWidth;      do {        await sleepMs(100);        newWidth = text.getBoundingClientRect().width;      } while (newWidth < 0 || newWidth === originalWidth)      let response = await fetch(        testURI("ctr", "font", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

An iframe is an element in a web page than allows websites to embed a second web page. Caching of this web page could be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      iframe.addEventListener("load", () => resolve(key), {once: true});      iframe.src = testURI("resource", "page", key);    })read: async (key) => {      let iframe = document.createElement("iframe");      document.body.appendChild(iframe);      let iframeLoadPromise = new Promise((resolve, reject) => {        iframe.addEventListener("load", resolve, {once: true});      });      let address = testURI("resource", "page", key);      iframe.src = address;      await iframeLoadPromise;      let response = await fetch(        testURI("ctr", "page", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Caching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let img = document.createElement("img");      document.body.appendChild(img);      img.addEventListener("load", () => resolve(key), {once: true});      img.src = testURI("resource", "image", key);    })read: async (key) => {      let img = document.createElement("img");      document.body.appendChild(img);      let imgLoadPromise = new Promise((resolve, reject) => {        img.addEventListener("load", resolve, {once: true});      });      img.src = testURI("resource", "image", key);      await imgLoadPromise;      let response = await fetch(        testURI("ctr", "image", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p,dad47994-1478-4269-bc67-9d5be7279695_3p,a224b08b-56ca-430a-8291-a1391ce3f527_3p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3presult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p,dad47994-1478-4269-bc67-9d5be7279695_3p,a224b08b-56ca-430a-8291-a1391ce3f527_3p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p,9e792e5f-2682-45df-a4b6-9926c1368572_3p,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p,be33e986-4227-4dad-98ab-849158191238_3p,d1bff213-a9f5-41c3-a065-c8b074cff472_3presult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p,9e792e5f-2682-45df-a4b6-9926c1368572_3p,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p,be33e986-4227-4dad-98ab-849158191238_3p,d1bff213-a9f5-41c3-a065-c8b074cff472_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session: undefinedresult, different session: undefinedunsupported: truepassed: undefinedtest failed: false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_3p,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p,6a79070f-7300-4f0a-b3e4-67db8452282d_3p,fc4e16e7-ac2e-48a9-8623-332158912d29_3p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3presult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_3p,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p,6a79070f-7300-4f0a-b3e4-67db8452282d_3p,fc4e16e7-ac2e-48a9-8623-332158912d29_3p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p,3c6d0906-4d80-439c-9124-ff2647fc503f_3p,29934d34-345f-4b44-91a5-4cfc4705276b_3p,c261a896-1dbf-455d-8a32-c51b15883279_3p,4befec68-5b8d-4639-b156-03db7501a173_3presult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p,3c6d0906-4d80-439c-9124-ff2647fc503f_3p,29934d34-345f-4b44-91a5-4cfc4705276b_3p,c261a896-1dbf-455d-8a32-c51b15883279_3p,4befec68-5b8d-4639-b156-03db7501a173_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:15e21312-33db-4994-b766-baad8032803f_3p,7ccbfb90-229d-427c-9f22-79caffc2fec3_3p,ab247bb9-7408-43c0-81f4-22f7335617f7_3p,1cc5af75-9209-4c31-a70b-5f98374d6544_3p,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_3presult, different session: undefinedunsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecureresult, different session:Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecure,Error: IDBFactory.open: The operation is insecureunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p,299e3cd4-7953-4f77-801f-8985b822ac24_3p,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p,d31fb840-54e6-4419-b2ca-f532e60327ac_3p,8003e0ac-cbd3-4236-932f-a79792d54b62_3presult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p,299e3cd4-7953-4f77-801f-8985b822ac24_3p,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p,d31fb840-54e6-4419-b2ca-f532e60327ac_3p,8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session: , fe4b6d38-97a5-47e0-8ce9-abd6b175891b_3p, 576d3332-f9c6-455d-bddd-b3b643b6c552_3presult, different session: undefinedunsupported: true, false, true, true, falsepassed: , true, truetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session: Error: IDBFactory.open: The operation is insecureresult, different session: Error: IDBFactory.open: The operation is insecureunsupported: truepassed: undefinedtest failed: false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:24441439-f1db-4c84-bc96-50682c4e643e_3p,6d1c53c8-70cf-47eb-9a21-0ba706352479_3p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_3p,e198d1f6-c1a6-4343-9907-302129e685e7_3p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_3presult, different session:24441439-f1db-4c84-bc96-50682c4e643e_3p,6d1c53c8-70cf-47eb-9a21-0ba706352479_3p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_3p,e198d1f6-c1a6-4343-9907-302129e685e7_3p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (secret) => {      try {        return await IdbKeyVal.set("secret", secret);      } catch (e) {        throw new Error("Unsupported");      }    }read: () => IdbKeyVal.get("secret")result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p,e74254c5-9034-45cd-b7ba-b7db726e55ab_3presult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p,e74254c5-9034-45cd-b7ba-b7db726e55ab_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p,dad47994-1478-4269-bc67-9d5be7279695_3p,a224b08b-56ca-430a-8291-a1391ce3f527_3p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3presult, different session:e7085635-2c69-4e98-92d3-97e4c73afa2f_3p,dad47994-1478-4269-bc67-9d5be7279695_3p,a224b08b-56ca-430a-8291-a1391ce3f527_3p,ed625f5b-53f1-45e2-b9d8-f1afa4b755d4_3p,54ad99c6-a8ab-4b8b-957e-aaa49d517db0_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p,9e792e5f-2682-45df-a4b6-9926c1368572_3p,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p,be33e986-4227-4dad-98ab-849158191238_3p,d1bff213-a9f5-41c3-a065-c8b074cff472_3presult, different session:99f0a2bf-b41a-4758-8d51-b9c5d07dd116_3p,9e792e5f-2682-45df-a4b6-9926c1368572_3p,96cb1992-e972-4aef-8062-ef9c5ed16a01_3p,be33e986-4227-4dad-98ab-849158191238_3p,d1bff213-a9f5-41c3-a065-c8b074cff472_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session: nullresult, different session: nullunsupported: truepassed: undefinedtest failed: false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:026115d8-5ec8-4705-b68d-299ea05d729f_3p,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p,6a79070f-7300-4f0a-b3e4-67db8452282d_3p,fc4e16e7-ac2e-48a9-8623-332158912d29_3p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3presult, different session:026115d8-5ec8-4705-b68d-299ea05d729f_3p,b33c419d-acf6-4795-95e0-d5d753f2f16d_3p,6a79070f-7300-4f0a-b3e4-67db8452282d_3p,fc4e16e7-ac2e-48a9-8623-332158912d29_3p,311d701c-ad7e-4aa7-84a2-afdf4a4a400b_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p,3c6d0906-4d80-439c-9124-ff2647fc503f_3p,29934d34-345f-4b44-91a5-4cfc4705276b_3p,c261a896-1dbf-455d-8a32-c51b15883279_3p,4befec68-5b8d-4639-b156-03db7501a173_3presult, different session:a89ceebb-1801-46fc-bbfa-9268cd1e86b8_3p,3c6d0906-4d80-439c-9124-ff2647fc503f_3p,29934d34-345f-4b44-91a5-4cfc4705276b_3p,c261a896-1dbf-455d-8a32-c51b15883279_3p,4befec68-5b8d-4639-b156-03db7501a173_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:15e21312-33db-4994-b766-baad8032803f_3p,7ccbfb90-229d-427c-9f22-79caffc2fec3_3p,ab247bb9-7408-43c0-81f4-22f7335617f7_3p,1cc5af75-9209-4c31-a70b-5f98374d6544_3p,f1e4b993-6e6c-430d-bd4c-f9214ee02e71_3presult, different session: , , , ,unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.result, different session:Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.,Error: The operation is insecure.unsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p,299e3cd4-7953-4f77-801f-8985b822ac24_3p,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p,d31fb840-54e6-4419-b2ca-f532e60327ac_3p,8003e0ac-cbd3-4236-932f-a79792d54b62_3presult, different session:3ae57aff-59cf-478f-83e7-0ce6e2ef84fd_3p,299e3cd4-7953-4f77-801f-8985b822ac24_3p,aad11fab-6660-48f9-b28d-4b2ee45a44df_3p,d31fb840-54e6-4419-b2ca-f532e60327ac_3p,8003e0ac-cbd3-4236-932f-a79792d54b62_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session: , fe4b6d38-97a5-47e0-8ce9-abd6b175891b_3p, , , 576d3332-f9c6-455d-bddd-b3b643b6c552_3presult, different session: , , , ,unsupported: true, false, true, true, falsepassed: , true, truetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session: Error: The operation is insecure.result, different session: Error: The operation is insecure.unsupported: truepassed: undefinedtest failed: false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:24441439-f1db-4c84-bc96-50682c4e643e_3p,6d1c53c8-70cf-47eb-9a21-0ba706352479_3p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_3p,e198d1f6-c1a6-4343-9907-302129e685e7_3p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_3presult, different session:24441439-f1db-4c84-bc96-50682c4e643e_3p,6d1c53c8-70cf-47eb-9a21-0ba706352479_3p,5894b594-2a38-4d3a-be5d-e53e01ad93d1_3p,e198d1f6-c1a6-4343-9907-302129e685e7_3p,bf62e3cc-149e-4225-8d7b-3b8b3b338e10_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (secret) => localStorage.setItem("secret", secret)read: () => localStorage.getItem("secret")result, same session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p,e74254c5-9034-45cd-b7ba-b7db726e55ab_3presult, different session:9d7140bd-04e0-44f3-b6d6-e0234d82e99b_3p,5a8cb80f-21db-4a7c-bd79-071d7e26aeb7_3p,32f534ec-f0c9-4fb9-a393-c743feebc30e_3p,085080b8-ac7e-4d13-b00e-fceb219d3dac_3p,e74254c5-9034-45cd-b7ba-b7db726e55ab_3punsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: Error: No requests receivedresult, different session: Error: No requests receivedunsupported: truepassed: undefinedtest failed: false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedresult, different session:Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests received,Error: No requests receivedunsupported: true, true, true, true, truepassed: undefinedtest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: Error: No requests receivedresult, different session: Error: No requests receivedunsupported: truepassed: undefinedtest failed: false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      return key;    }read: async (key) => {      let link = document.createElement("link");      link.rel = "prefetch";      link.href = testURI("resource", "prefetch", key);      document.getElementsByTagName("head")[0].appendChild(link);      await sleepMs(500);      let response = await fetch(        testURI("ctr", "prefetch", key), {"cache": "reload"});      let countString = (await response.text()).trim();      if (parseInt(countString) === 0) {        throw new Error("No requests received");      }      return countString;    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Caching of scripts in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: (key) => new Promise((resolve, reject) => {      let script = document.createElement("script");      document.body.appendChild(script);      script.addEventListener("load", () => resolve(key), {once: true});      script.src = testURI("resource", "script", key);    })read: async (key) => {      let script = document.createElement("script");      document.body.appendChild(script);      let scriptLoadPromise = new Promise((resolve, reject) => {        script.addEventListener("load", resolve, {once: true});      });      script.src = testURI("resource", "script", key);      await scriptLoadPromise;      let response = await fetch(        testURI("ctr", "script", key), {"cache": "reload"});      return (await response.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1result, different session: 1unsupported: falsepassed: falsetest failed: false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 2, 2, 2, 2, 2unsupported: false, false, false, false, falsepassed: true, true, true, true, truetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1result, different session: 2unsupported: falsepassed: truetest failed: false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

write: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      return key;    }read: async (key) => {      const req = new XMLHttpRequest();      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));      req.open("GET", testURI("resource", "xhr", key));      req.send();      await loadPromise;      let countResponse = await fetch(testURI("ctr", "xhr", key),                                      {cache: "reload"});      return (await countResponse.text()).trim();    }result, same session: 1, 1, 1, 1, 1result, different session: 1, 1, 1, 1, 1unsupported: false, false, false, false, falsepassed: false, false, false, false, falsetest failed: false, false, false, false, false

  Checks whether the browser decides to use  encrypted DNS if the computer is located in Brazil.

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: falseleak detected: true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, trueleak detected: true, true, true, true, false

passed: false, false, false, false, trueleak detected: true, true, true, true, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

  Checks whether the browser decides to use  encrypted DNS if the computer is located in China.

passed: false, true, false, true, falseleak detected: true, false, true, false, true

passed: false, true, false, true, falseleak detected: true, false, true, false, true

passed: falseleak detected: true

passed: false, true, false, true, falseleak detected: true, false, true, false, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, true, false, true, falseleak detected: true, false, true, false, true

passed: false, true, false, true, falseleak detected: true, false, true, false, true

passed: trueleak detected: false

passed: false, true, false, true, falseleak detected: true, false, true, false, true

passed: false, true, false, true, falseleak detected: true, false, true, false, true

  Checks whether the browser decides to use  encrypted DNS if the computer is located in Germany.

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: falseleak detected: true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

  Checks whether the browser decides to use  encrypted DNS if the computer is located in India.

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: falseleak detected: true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

  Checks whether the browser decides to use  encrypted DNS if the computer is located in Nigeria.

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: falseleak detected: true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, true, false, false, falseleak detected: true, false, true, true, true

passed: false, true, false, false, falseleak detected: true, false, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

  Checks whether the browser decides to use  encrypted DNS if the computer is located in Russia.

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: falseleak detected: true

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: false, true, false, false, falseleak detected: true, false, true, true, true

passed: false, true, false, false, falseleak detected: true, false, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: trueleak detected: false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

  Checks whether the browser decides to use  encrypted DNS if the computer is located in United States.

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: falseleak detected: true

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: trueleak detected: false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

passed: false, false, true, false, trueleak detected: true, true, false, true, false

  Checks whether the browser decides to use  encrypted DNS if the operating system's default DNS provider is Cloudflare.

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: trueleak detected: false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

  Checks whether the browser decides to use  encrypted DNS if the operating system's default DNS provider is Comodo.

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: falseleak detected: true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

  Checks whether the browser decides to use  encrypted DNS if the operating system's default DNS provider is Google.

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: trueleak detected: false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

  Checks whether the browser decides to use  encrypted DNS if the operating system's default DNS provider is Quad9.

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: true, true, true, true, trueleak detected: false, false, false, false, false

passed: trueleak detected: false

passed: false, false, false, false, falseleak detected: true, true, true, true, true

passed: false, false, false, false, falseleak detected: true, true, true, true, true