WebVTT
Web Video Text Tracks
The W3C web standard for subtitles. Used by HTML5 <track> elements. Like SRT but with dot-separated milliseconds and styling support.
In depth
WebVTT (.vtt) is the W3C-standard subtitle format used by HTML5 <track> elements. It evolved from SRT and shares the same general layout, but uses dot-separated milliseconds (00:00:01.500 instead of 00:00:01,500), supports cue settings for positioning and alignment, allows inline styling via cue tags, and includes optional metadata blocks. Every modern browser parses VTT natively.
When to use it
Use VTT when delivering captions on the web with HTML5 <video>. It's the only format browsers will read from a <track> element. YouTube also accepts VTT uploads.
Example
WEBVTT 00:00:01.000 --> 00:00:03.500 line:90% Hello world.
Frequently asked
Why does WebVTT use dots and not commas?+
WebVTT follows the ISO 8601 / W3C convention of using a period as the decimal separator. SRT uses a comma because it originated in European software.
What are cue settings?+
Optional space-separated key:value pairs after the timestamp — for example `line:90%` (vertical position), `align:center` (text alignment), `position:50%` (horizontal). They let you place captions outside the bottom-center default.
Can VTT files be styled with CSS?+
Yes — the ::cue pseudo-element targets WebVTT text, so site CSS can override font, color, and background.
The most common subtitle file format. Plain text with numbered cues and HH:MM:SS,mmm timestamps.
A heavily-styled subtitle format used by Aegisub and the anime fansub community. Supports per-cue fonts, colors, positioning, and karaoke timing.
Subtitles permanently rendered into the video frame. They can't be turned off, but they look identical on every player and platform.