VideoTrackList.length

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.

Syntax

var trackCount = VideoTrackList.length;

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.

Example

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

var videoElem = document.querySelector("video");
var 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 Status Comment
HTML Living Standard
The definition of 'VideoTrackList: length' in that specification.
Living Standard  

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic supportChrome Full support 45
Disabled
Full support 45
Disabled
Disabled From version 45: this feature is behind the enable-experimental-web-platform-features preference (needs to be set to enabled). To change preferences in Chrome, visit chrome://flags.
Edge Full support 12Firefox Full support 33
Disabled
Full support 33
Disabled
Disabled From version 33: this feature is behind the media.track.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE Full support 10Opera Full support 32
Disabled
Full support 32
Disabled
Disabled From version 32: this feature is behind the enable-experimental-web-platform-features preference (needs to be set to enabled).
Safari Full support 6.1WebView Android Full support 45Chrome Android Full support 45
Disabled
Full support 45
Disabled
Disabled From version 45: this feature is behind the enable-experimental-web-platform-features preference (needs to be set to enabled). To change preferences in Chrome, visit chrome://flags.
Edge Mobile Full support YesFirefox Android Full support 33
Disabled
Full support 33
Disabled
Disabled From version 33: this feature is behind the media.track.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 32
Disabled
Full support 32
Disabled
Disabled From version 32: this feature is behind the enable-experimental-web-platform-features preference (needs to be set to enabled).
Safari iOS Full support 7.1Samsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown
User must explicitly enable this feature.
User must explicitly enable this feature.

Document Tags and Contributors

Contributors to this page: sideshowbarker
Last updated by: sideshowbarker,