HTML DOM Audio audioTracks Property

Definition and Usage

A single media file can contain several audio tracks, for example different languages or a commentary track. The audioTracks property exposes them as an array-like AudioTrackList, where each AudioTrack has properties such as id, kind, label, language and a writable enabled flag.

Syntax

mediaElement.audioTracks

This returns an AudioTrackList. Its length property tells you how many audio tracks exist, and you can index into it like an array.

Example: listing audio tracks

const video = document.getElementById("myVideo");

video.addEventListener("loadedmetadata", () => {
  const tracks = video.audioTracks;
  console.log("Number of audio tracks:", tracks.length);

  for (let i = 0; i < tracks.length; i++) {
    console.log(tracks[i].language, "-", tracks[i].label);
  }
});

Each entry is an AudioTrack. Setting a track's enabled property to true or false turns that audio track on or off during playback, which is how you build a language switcher.

// Enable the first track, mute all others
const tracks = video.audioTracks;
for (let i = 0; i < tracks.length; i++) {
  tracks[i].enabled = (i === 0);
}