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

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
TextTrack
23
12
31
Firefox versions before Firefox 50 didn't display captions when playing media without one or more video tracks being played.
10
≤12.1
6
4.4
25
31
≤12.1
7
1.5
activeCues
23
12
31
Starting in Firefox 69, cues are no longer incorrectly loaded when the TextTrack's mode is disabled; if that's the case, the returned list is empty.
10
≤12.1
6
4.4
25
31
≤12.1
7
1.5
addCue
23
12
31
10
≤12.1
6
4.4
25
31
≤12.1
7
1.5
cuechange_event
Yes
12
31
10
?
Yes
Yes
Yes
31
No
Yes
Yes
cues
23
12
31
Starting in Firefox 69, cues are no longer incorrectly loaded when the TextTrack's mode is disabled; if that's the case, the returned list is empty.
10
≤12.1
6
4.4
25
31
≤12.1
7
1.5
id
33
12
31
No
20
7
4.4.3
33
31
20
7
2.0
inBandMetadataTrackDispatchType
No
12
31
No
No
7
No
No
31
No
7
No
kind
23
12
31
10
≤12.1
6
4.4
25
31
≤12.1
7
1.5
label
23
12
31
10
≤12.1
6
4.4
25
31
≤12.1
7
1.5
language
23
12
31
10
≤12.1
6
4.4
25
31
≤12.1
7
1.5
mode
23
12
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
≤12.1
6
4.4
25
31
≤12.1
7
1.5
oncuechange
23
12
31
10
≤12.1
6
4.4
25
31
≤12.1
8
1.5
removeCue
23
12
31
10
≤12.1
6
4.4
25
31
≤12.1
7
1.5
sourceBuffer
No
No
No
No
No
8
No
No
No
No
13
Exposed in Mobile Safari on iPad but not on iPhone.
No

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/TextTrack