HTMLTrackElement

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The HTMLTrackElement interface represents an HTML <track> element within the DOM. This element can be used as a child of either <audio> or <video> to specify a text track containing information such as closed captions or subtitles.

Properties

Inherits properties from its parent, HTMLElement.

HTMLTrackElement.kind
Is a DOMString that reflects the kind HTML attribute, indicating how the text track is meant to be used. Possible values are: subtitles, captions, descriptions, chapters, or metadata.
HTMLTrackElement.src
Is a DOMString that reflects the src HTML attribute, indicating the address of the text track data.
HTMLTrackElement.srclang
Is a DOMString that reflects the srclang HTML attribute, indicating the language of the text track data.
HTMLTrackElement.label
Is a DOMString that reflects the label HTML attribute, indicating a user-readable title for the track.
HTMLTrackElement.default
A Boolean reflecting the default  attribute, indicating that the track is to be enabled if the user's preferences do not indicate that another track would be more appropriate.
HTMLTrackElement.readyState Read only
Returns  an unsigned short that show the readiness state of the track:
Constant Value Description
NONE 0 Indicates that the text track's cues have not been obtained.
LOADING 1 Indicates that the text track is loading and there have been no fatal errors encountered so far. Further cues might still be added to the track by the parser.
LOADED 2 Indicates that the text track has been loaded with no fatal errors.
ERROR 3 Indicates that the text track was enabled, but when the user agent attempted to obtain it, this failed in some way. Some or all of the cues are likely missing and will not be obtained.
HTMLTrackElement.track Read only
Returns TextTrack is the track element's text track data.

Methods

No specific method; inherits methods from its parent, HTMLElement.

Events

The following events may be fired on a <track> element, in addition to any that may be fired at its parent, HTMLElement.

cuechange
Sent when the underlying TextTrack has changed the currently-presented cues. This event is always sent to the TextTrack but is also sent to the HTMLTrackElement if one is associated with the track.
You may also use the oncuechange event handler to establish a handler for this event.

Usage notes

Loading of the track's text resource

The WebVTT or TTML data describing the actual cues for the text track isn't loaded if the track's mode is initially in the disabled state. If you need to be able to perform any processing on the track after the <track> is set up, you should instead ensure that the track's mode is either hidden (if you don't want it to start out being presented to the user) or showing (to initially display the track). You can then change the mode as desired later.

Specifications

Specification Status Comment
HTML Living Standard
The definition of 'HTMLTrackElement' in that specification.
Living Standard
HTML5
The definition of 'HTMLTrackElement' in that specification.
Recommendation Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
HTMLTrackElementChrome Full support 23Edge Full support YesFirefox Full support 31
Notes
Full support 31
Notes
Notes Prior to Firefox 50, text tracks would only load if the <track> element is in a document.
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 12Safari Full support YesWebView Android Full support YesChrome Android Full support 25Firefox Android Full support 31
Notes
Full support 31
Notes
Notes Prior to Firefox 50, text tracks would only load if the <track> element is in a document.
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 12Safari iOS Full support YesSamsung Internet Android ?
cuechange eventChrome Full support YesEdge ? Firefox Full support 68IE No support NoOpera ? Safari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support 68Opera Android ? Safari iOS Full support YesSamsung Internet Android ?
defaultChrome Full support 23Edge Full support 12Firefox Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 12Safari Full support YesWebView Android Full support YesChrome Android Full support 25Firefox Android Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 12Safari iOS Full support YesSamsung Internet Android ?
kindChrome Full support 23Edge Full support 12Firefox Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 12Safari Full support YesWebView Android Full support YesChrome Android Full support 25Firefox Android Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 12Safari iOS Full support YesSamsung Internet Android ?
labelChrome Full support 23Edge Full support 12Firefox Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 12Safari Full support YesWebView Android Full support YesChrome Android Full support 25Firefox Android Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 12Safari iOS Full support YesSamsung Internet Android ?
readyStateChrome Full support 23Edge Full support 12Firefox Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 12Safari Full support YesWebView Android Full support YesChrome Android Full support 25Firefox Android Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 12Safari iOS Full support YesSamsung Internet Android ?
srcChrome Full support 23Edge Full support 12Firefox Full support 31
Notes
Full support 31
Notes
Notes Setting the src property did not work properly in versions prior to 50.
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 12Safari Full support YesWebView Android Full support YesChrome Android Full support 25Firefox Android Full support 31
Notes
Full support 31
Notes
Notes Setting the src property did not work properly in versions prior to 50.
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 12Safari iOS Full support YesSamsung Internet Android ?
srclangChrome Full support 23Edge Full support 12Firefox Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 12Safari Full support YesWebView Android Full support YesChrome Android Full support 25Firefox Android Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 12Safari iOS Full support YesSamsung Internet Android ?
trackChrome Full support 23Edge Full support 12Firefox Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 12Safari Full support YesWebView Android Full support YesChrome Android Full support 25Firefox Android Full support 31
Full support 31
No support 24 — 30
Disabled
Disabled From version 24 until version 30 (exclusive): this feature is behind the media.webvtt.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 12Safari iOS Full support YesSamsung Internet Android ?

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
See implementation notes.
See implementation notes.
User must explicitly enable this feature.
User must explicitly enable this feature.

See also

  • The HTML element implementing this interface: <track>.