The kind property contains a string indicating the category of video contained in the VideoTrack.

The kind can be used to determine the scenarios in which specific tracks should be enabled or disabled. See Video track kind strings for a list of the kinds available for video tracks.

A string specifying the type of content the media represents. The string is one of those found in Video track kind strings below.

The kinds available for video tracks are:

"alternative"

A potential alternative to the main track, such as a different video take or a version of the soundtrack with only the music and no dialogue.

"captions"

A version of the main video track with captions burnt in.

"main"

The primary video track.

"sign"

A sign-language interpretation of an audio track.

"subtitles"

A version of the main video track with subtitles burnt in.

"commentary"

A video track containing a commentary. This might be used to contain the director's commentary track on a movie, for example.

"" (empty string)

The track doesn't have an explicit kind, or the kind provided by the track's metadata isn't recognized by the user agent.