Web/API/TextTrackList/length

The read-only TextTrackList property length returns the number of entries in the TextTrackList, each of which is a TextTrack representing one track in the media element. A value of 0 indicates that there are no text tracks in the media.

Syntax

var trackCount = TextTrackList.length;

Value

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

Example

This snippet gets the number of text tracks in the first media element found in the [[../../../../Glossary/DOM|DOM]] by querySelector().

var mediaElem = document.querySelector("video, audio");
var numTextTracks = 0;

if (mediaElem.textTracks) {
  numTextTracks = mediaElem.textTracks.length;
}

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

Specifications

Specification	Status	Comment
HTML Living StandardThe definition of 'TextTrackList: length' in that specification.	Living Standard

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
length	Chrome Full support 44	Edge Full support ≤18	Firefox Full support Yes	IE ?	Opera Full support 31	Safari Full support 10	WebView Android Full support 44	Chrome Android Full support 44	Firefox Android ?	Opera Android Full support 32	Safari iOS ?	Samsung Internet Android Full support 4.0

Legend

Full support  

Full support

Compatibility unknown  

Compatibility unknown

TextTrackList.length by Mozilla Contributors is licensed under CC-BY-SA 2.5.