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TextTrack

The TextTrack interface—part of the API for handling WebVTT (text tracks on media presentations)—describes and controls the text track associated with a particular <track> element.

Properties

This interface also inherits properties from EventTarget.

TextTrack.activeCues Read only: A TextTrackCueList object listing the currently active set of text track cues. Track cues are active if the current playback position of the media is between the cues' start and end times.
TextTrack.cues Read only: A TextTrackCueList which contains all of the track's cues.
TextTrack.id Read only: A DOMString which identifies the track, if it has one. If it doesn't have an ID, then this value is an empty string (""). If the TextTrack is associated with a <track> element, then the track's ID matches the element's ID.
TextTrack.inBandMetadataTrackDispatchType Read only: Returns a DOMString which indicates the track's in-band metadata track dispatch type. needs details
TextTrack.kind Read only: Returns a DOMString indicating what kind of text track the TextTrack describes. The value must be one of those in the TextTrackKind enum.
TextTrack.label Read only: A human-readable DOMString which contains the text track's label, if one is present; otherwise, this is an empty string (""), in which case a custom label may need to be generated by your code using other attributes of the track, if the track's label needs to be exposed to the user.
TextTrack.language Read only: A DOMString which specifies the text language in which the text track's contents is written. The value must adhere to the format specified in the Tags for Identifying Languages (BCP 47) document from the IETF, just like the HTML lang attribute. For example, this can be "en-US" for United States English or "pt-BR" for Brazilian Portuguese.
TextTrack.mode: A DOMString specifying the track's current mode. Changing this property's value changes the track's current mode to match. Permitted values are listed under Text track mode constants.

Event handlers

TextTrack.oncuechange: A EventHandler specifying a function to be called when a cuechange event occurs. Handling these events lets you know when cues are entered and exited. A given text cue appears when the cue is entered and disappears when the cue is exited.

Methods

This interface also inherits methods from EventTarget.

TextTrack.addCue(): Adds a cue (specified as a TextTrackCue object to the track's list of cues.
TextTrack.removeCue(): Removes a cue (specified as a TextTrackCue object from the track's list of cues.

Example

tbd

Specifications

Specification	Status	Comment
WebVTT: The Web Video Text Tracks Format	Candidate Recommendation

Browser compatibilityUpdate compatibility data on GitHub

	Desktop
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic support	18	12	31 31 Firefox versions before Firefox 50 didn't display captions when playing media without one or more video tracks being played.	10	15	6
`activeCues`	18	12	31	10	15	6
`cues`	18	12	31	10	15	6
`id`	18	12	31	10	15	6
`inBandMetadataTrackDispatchType`	18	12	31	10	15	6
`kind`	18	12	31	10	15	6
`label`	18	12	31	10	15	6
`language`	18	12	31	10	15	6
`mode`	18	12	31 31 Before Firefox 52, using JavaScript to change the mode of a text track that's part of a media element would send one change event to the element's textTracks TextTrackList for each change, even if mutliple changes are made in a single pass through the Firefox event loop. Starting in Firefox 52, these changes are reflected by a single event.	10	15	6
`oncuechange`	Yes	12	31	?	?	?
`addCue`	18	12	31	10	15	6
`removeCue`	18	12	31	10	15	6
`sourceBuffer`	?	?	?	?	?	?

	Mobile
	Android webview	Chrome for Android	Edge Mobile	Firefox for Android	Opera for Android	iOS Safari	Samsung Internet
Basic support	4.4	18	No	31	No	7.1	Yes
`activeCues`	4.4	18	No	31	No	7.1	Yes
`cues`	4.4	18	No	31	No	7.1	Yes
`id`	4.4	18	No	31	No	7.1	Yes
`inBandMetadataTrackDispatchType`	4.4	18	No	31	No	7.1	Yes
`kind`	4.4	18	No	31	No	7.1	Yes
`label`	4.4	18	No	31	No	7.1	Yes
`language`	4.4	18	No	31	No	7.1	Yes
`mode`	4.4	18	No	31	No	7.1	Yes
`oncuechange`	Yes	Yes	No	31	No	?	Yes
`addCue`	4.4	18	No	31	No	7.1	Yes
`removeCue`	4.4	18	No	31	No	7.1	Yes
`sourceBuffer`	?	?	?	?	?	?	?