SRT, VTT or burned-in captions?
By the maker of Captions Cut. Facts checked on from the pages listed under Sources.
The short answer
SRT is the simplest caption file and the one most platforms take (YouTube, Facebook, LinkedIn, X). WebVTT (.vtt) is the web standard, with positioning; YouTube takes it. Burned-in captions are part of the picture: every viewer sees them, styled as you chose, on TikTok and Instagram too, which take no caption file. For short-form video, burn them in, and add an SRT where the platform accepts one.
SRT (SubRip)
A plain text file of numbered cues. Each has a start and end time written hours:minutes:seconds,milliseconds and separated by -->, then the text, then a blank line. There is no formal standard; the Library of Congress describes it as “not well standardized”, and players differ on styling.
1 00:00:00,000 --> 00:00:01,360 Every word lands 2 00:00:01,360 --> 00:00:02,800 right on time
WebVTT (.vtt)
The W3C format the HTML <track> element uses. A file starts with WEBVTT, is always UTF-8, writes milliseconds after a full stop, and lets each cue set its line, position, size and alignment. It is a W3C Candidate Recommendation.
Who takes which
| Platform | SRT | VTT |
|---|---|---|
| YouTube | Yes | Yes |
| Facebook (Page and profile videos, ads) | Yes | Not stated |
| LinkedIn (desktop, ads) | Yes | Not stated |
| X (web) | Yes | Not stated |
| TikTok, Instagram, Snapchat | Not stated | Not stated |
When to burn captions in
- The platform takes no file (TikTok, Instagram Reels, Snapchat).
- You want a style: a font, a colour, the spoken word highlighted.
- The clip will be downloaded, reposted or embedded, where a separate file would be lost.
The cost is control: a viewer cannot switch burned-in captions off or resize them. Captions Cut exports the burned-in video and, from the same transcript, an SRT file timed to it.
Questions
Can I convert SRT to VTT?
Yes: add a WEBVTT line at the top and change the comma before the milliseconds to a full stop. Cue numbers are optional in VTT.
Which caption file does Instagram accept?
Instagram’s help pages describe no caption file upload for Reels. Use its own closed captions, or burn captions into the video.
Sources
- Library of Congress: SubRip
- W3C: WebVTT
- YouTube: supported caption files
- Facebook: captions for video ads
- LinkedIn: add a caption file
- X: upload a caption file
Each page read on .