WebVTT

WebVTT, short for Web Video Text Tracks, is a text-based format for displaying timed text tracks such as captions, subtitles, descriptions, and chapters for video and audio content on the web. It is designed to work with HTML5 media elements and the track element, enabling synchronized display of text alongside media.

A WebVTT file is a plain text file with a header line WEBVTT, followed by cues. Each cue has a start time and end time, then the cue text and optional cue settings that control alignment, line position, size, and writing mode. The file extension is .vtt and the mime type is text/vtt. WebVTT supports multiple kinds of tracks: captions for the deaf and hard of hearing, subtitles for translation, descriptions for the video content, and chapters for navigation.

In HTML, a track element references a WebVTT file and can specify kind, srclang, and label. JavaScript can access cues via the TextTrack API for dynamic control. The WebVTT format is plain text and editable, which simplifies authoring and accessibility.

Compatibility and standards: WebVTT is a W3C Recommendation and is supported by major browsers such as Chrome, Firefox, Edge, and Safari, as well as many mobile platforms. It is designed to be backward compatible with older captioning practices while enabling richer timed text features.