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. Thus, for displayed cues such as captions or subtitles, the active cues are currently being displayed.

TextTrack.cuesRead only

A TextTrackCueList which contains all of the track's cues.

TextTrack.idRead 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.inBandMetadataTrackDispatchTypeRead only

Returns a DOMString which indicates the track's in-band metadata track dispatch type.

TextTrack.kindRead only

Returns a DOMString indicating what kind of text track the TextTrack describes. It must be one of the permitted values.

TextTrack.labelRead 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.languageRead 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, which must be one of the permitted values. Changing this property's value changes the track's current mode to match. The default is disabled, unless the <track> element's default Boolean attribute is specified, in which case the default mode is started.

Events

cuechange

Fired when cues are entered and exited. A given text cue appears when the cue is entered and disappears when the cue is exited. Also available via the oncuechange property.

Methods

This interface also inherits methods from EventTarget.

Note: The TextTrackCue interface is an abstract class used as the parent for other cue interfaces such as VTTCue. Therefore, when adding or removing a cue you will be passing in one of the cue types that inherit from TextTrackCue.

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

The following example adds a new TextTrack to a video, then sets it to display using TextTrack.mode.

let video = document.querySelector('video');
let track = video.addTextTrack("captions", "Captions", "en");
track.mode = "showing";

Specifications

Specification
HTML Standard (HTML)
# texttrack

Browser compatibility

BCD tables only load in the browser

See also