Updated July 29, 2026
SRT and VTT Caption Format Reference
SRT and WebVTT are plain-text caption formats. The timing lines are the fragile part: clean text carefully without changing cue times unless you intend to retime captions.
Core lines
| Format | Part | Example |
|---|---|---|
| SRT | Cue number | 1 |
| SRT | Timing | 00:00:01,000 --> 00:00:04,000 |
| SRT | Caption text | Hello world |
| VTT | Header | WEBVTT |
| VTT | Timing | 00:00:01.000 --> 00:00:04.000 |
| VTT | Caption text | Hello world |
Do not clean timing like proseWhitespace cleanup is useful for caption text, but timestamp arrows, commas, periods, and cue identifiers should be preserved unless you are deliberately converting formats.
References
Questions
What is the main difference between SRT and VTT?
SRT is simpler and uses comma milliseconds. WebVTT starts with a WEBVTT header and uses period milliseconds, with optional web caption features.
Can I remove caption timestamps?
Yes, when you want a plain transcript. Keep timestamps when you still need a valid subtitle file.