BackgroundFetchManager

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental:This is anexperimental technology
Check theBrowser compatibility table carefully before using this in production.

Note: This feature is available inWeb Workers.

TheBackgroundFetchManager interface of theBackground Fetch API is a map where the keys are background fetch IDs and the values areBackgroundFetchRegistration objects.

Instance properties

None.

Instance methods

fetch()Experimental: Returns a Promise that resolves with aBackgroundFetchRegistration object for a supplied array of URLs andRequest objects.
get()Experimental: Returns a Promise that resolves with theBackgroundFetchRegistration associated with the providedid orundefined if theid is not found.
getIds()Experimental: Returns the IDs of all registered background fetches.

Examples

The example below shows how to get an instance ofBackgroundFetchManager from aServiceWorkerRegistration object and callsfetch() to download an audio file in the background.

navigator.serviceWorker.ready.then(async (swReg) => {  const bgFetch = await swReg.backgroundFetch.fetch(    "my-fetch",    ["/ep-5.mp3", "ep-5-artwork.jpg"],    {      title: "Episode 5: Interesting things.",      icons: [        {          sizes: "300x300",          src: "/ep-5-icon.png",          type: "image/png",        },      ],      downloadTotal: 60 * 1024 * 1024,    },  );});