selectorOptional

AMediaStreamTrack for which to gather statistics.If this isnull (the default value), statistics will be gathered for the entireRTCPeerConnection.

In older code and documentation, you may see a callback-based version of this function.This has been deprecated and its use isstrongly discouraged.You should update any existing code to use thePromise-based version ofgetStats() instead.The parameters for the older form ofgetStats() are described below, to aid in updating existing code.

successCallbackDeprecated

Acallback function called once the report has been successfully generated.

failureCallbackDeprecated

Acallback function called once the report has failed to be generated.

APromise which resolves with anRTCStatsReport object providing connection statistics.The report's contents depend on theselector and other details of the connection.

This method does not throw exceptions; instead, it rejects the returned promise with one of the following errors:

InvalidAccessErrorDOMException

Thrown when there is noRTCRtpSender orRTCRtpReceiver whosetrack matches the specifiedselector, orselector matches more than one sender or receiver.

This example creates a periodic function usingsetInterval() that collectsstatistics for anRTCPeerConnection every second, generating anHTML-formatted report and inserting it into a specific element in the DOM.

setInterval(() => {  myPeerConnection.getStats(null).then((stats) => {    let statsOutput = "";    stats.forEach((report) => {      statsOutput +=        `<h2>Report: ${report.type}</h2>\n<strong>ID:</strong> ${report.id}<br>\n` +        `<strong>Timestamp:</strong> ${report.timestamp}<br>\n`;      // Now the statistics for this report; we intentionally drop the ones we      // sorted to the top above      Object.keys(report).forEach((statName) => {        if (          statName !== "id" &&          statName !== "timestamp" &&          statName !== "type"        ) {          statsOutput += `<strong>${statName}:</strong> ${report[statName]}<br>\n`;        }      });    });    document.querySelector(".stats-box").innerHTML = statsOutput;  });}, 1000);

This works by callinggetStats(), then, when the promise is resolved, iterates over theRTCStatsReport objects on the returnedRTCStatsReport.A section is created for each report with a header and all of the statistics below, with the type, ID, and timestamp handled specially to place them at the top of the list.

Once theHTML for the report is generated, it is injected into the element whose class is"stats-box" by setting itsinnerHTML property.