VideoTrackList: length property

Limited availability

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

The read-only VideoTrackList property length returns the number of entries in the VideoTrackList, each of which is a VideoTrack representing one video track in the media element.

A value of 0 indicates that there are no video tracks in the media.

Value

A number indicating how many video tracks are included in the VideoTrackList. Each track can be accessed by treating the VideoTrackList as an array of objects of type VideoTrack.

Examples

This snippet gets the number of video tracks in the first <video> element found in the DOM by querySelector().

js
const videoElem = document.querySelector("video");
let numVideoTracks = 0;

if (videoElem.videoTracks) {
  numVideoTracks = videoElem.videoTracks.length;
}

Note that this sample checks to be sure HTMLMediaElement.videoTracks is defined, to avoid failing on browsers without support for VideoTrack.

Specifications

Specification
HTML
# dom-videotracklist-length-dev

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
length

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
User must explicitly enable this feature.
Has more compatibility info.