If you have ever tried to add subtitles to a video and gotten lost in format names, this is the short version.
The actual difference
SRT and WebVTT are 95% the same format. Both are plain-text files with a list of timed cues. The differences are mostly cosmetic:
| Feature | SRT | WebVTT |
|---|---|---|
| Decimal separator in timestamps | comma , | period . |
| Required header | none | WEBVTT |
| Cue numbers | required | optional |
| Styling support | none | yes (colors, position, italic) |
| Standard developed by | community (2001) | W3C (2010) |
A simple SRT cue:
1
00:00:01,000 --> 00:00:04,000
First caption
The WebVTT equivalent:
WEBVTT
00:00:01.000 --> 00:00:04.000
First caption
If you replaced the commas with periods and added the WEBVTT header line, you converted SRT to WebVTT. That is literally the whole conversion for simple files.
Which one to use
Use SRT if
- You are sending subtitles to a video editor (Adobe Premiere, Final Cut, DaVinci Resolve all import SRT directly)
- You are uploading to YouTube (which accepts SRT)
- You are using VLC, MPV, or any desktop video player (all read SRT by default)
- You want maximum compatibility with old or custom playback systems
Use WebVTT if
- You are embedding video in a webpage with
<track src="captions.vtt">on a<video>element (this is the format browsers require) - You need styling (colors, italic, positioning) that SRT can not express
- You are working with an HTML5 video framework (Video.js, Plyr, JW Player)
Use SBV if
- You are downloading captions from YouTube Studio (which exports as SBV by default in some workflows)
- Otherwise, no real reason to use SBV in 2026
The gotchas
Timestamp decimal separator
The most common bug when converting by hand: forgetting to replace , with . in WebVTT timestamps. The file looks fine, your editor opens it, but the video player ignores every cue silently because the timestamps fail the WebVTT spec parser.
Our SRT to WebVTT converter handles this automatically. So does our WebVTT to SRT converter in the reverse direction.
Cue numbers
SRT requires every cue to have a sequential number on its own line before the timestamp. WebVTT makes this optional. When you convert WebVTT → SRT, our tool adds the cue numbers. When you convert SRT → WebVTT, we drop them since they were never required.
If you see your converted SRT missing the cue numbers, it was likely produced by a tool that emitted SRT-without-numbers (which technically violates the spec but many players accept). Our tool always emits valid SRT.
Multi-line cue text
Both formats support multi-line cue text (text spanning two or three lines on screen):
1
00:00:01,000 --> 00:00:04,000
First line of caption
Second line of caption
Both formats use a blank line as the cue terminator. If your cue text has a blank line in the middle, both formats split it into two separate cues. The fix: use only single line breaks within a cue.
Styling
WebVTT supports inline tags like <i>italic</i>, <b>bold</b>, <c.classname>colored</c>, and CSS-like positioning. When you convert WebVTT → SRT, all of that gets stripped because SRT has no styling. The text content survives but the formatting does not.
Encoding
Both formats are usually UTF-8. Older subtitle files (1990s and 2000s) sometimes use Windows-1252 or Shift-JIS for non-Latin scripts. Modern subtitle players auto-detect, but our converter assumes UTF-8 throughout. If your subtitles come out with garbled characters, the source file is in a different encoding and needs to be re-saved as UTF-8 first.
What about ASS and SSA?
Advanced SubStation Alpha (ASS) and SubStation Alpha (SSA) are full styling-aware subtitle formats popular in the anime community. They support multiple font styles per cue, vector-drawn karaoke effects, complex positioning. They are not interchangeable with SRT/WebVTT through simple conversion: you would lose 90% of the styling.
We do not currently convert ASS/SSA. For that workflow, use Aegisub or Subtitle Edit (both free, both desktop apps).
The one-line takeaway
SRT and WebVTT carry the same data. If you have one and you need the other, convert between them and the file will work in whatever tool was rejecting the original. The mechanics are trivial; the gotcha is just remembering which decimal separator each format uses.