SRT quality checker
To check subtitles, paste an SRT or WebVTT file or choose one, pick a preset and select Check subtitles. The tool lists every cue that has a line that is too long, too many lines, a reading speed that is too high, an overlap, a long gap or no text. It runs in your browser.
42 characters per line, 2 lines, 17 characters per second, 0.8–7 s per cue.
Don't have the file yet? Get subtitles from a YouTube link, or get the transcript as text.
Embed this tool
Paste this HTML into your page. The tool runs in your visitors' browsers; nothing they paste is uploaded.
How to check an SRT file in 3 steps
- Paste the subtitles, or choose an .srt or .vtt file up to 5 MB.
- Pick a preset and select Check subtitles. Select a problem to see its cue.
- Select Auto-fix for overlaps and order, then download the fixed SRT.
Example output
A short sample written by TubeTranscript (not a real video), run through this tool when the page was built.
Input
1 00:00:00,000 --> 00:00:03,000 This subtitle is easy to read. 2 00:00:02,500 --> 00:00:03,200 Too short and it overlaps the cue before. 3 00:00:03,500 --> 00:00:05,000 This line is far too long to fit comfortably on one subtitle line.
Output
3 cues checked: 5 problems in 2 cues. Cue 2 - Shown too briefly: Shown for 0.70 s (min 0.8 s). Cue 2 - Reads too fast: 48.6 characters per second (max 17). Cue 2 - Overlaps previous cue: Starts 0.50 s before the previous cue ends. Cue 3 - Line too long: A line has 66 characters (max 42). Cue 3 - Reads too fast: 36.0 characters per second (max 17).
What the checker looks at
| Check | What it reports |
|---|---|
| Line length | A line with more characters than the preset allows |
| Lines per cue | More lines than the preset allows |
| Reading speed | Characters per second above the preset |
| Cue length | A cue shown for less or more time than the preset allows |
| Overlap and order | A cue that starts before the previous one ends, or out of order |
| Gaps and empty cues | Long silences between cues, and cues without text |
The default preset allows 42 characters per line, 2 lines, 17 characters per second and 0.8 to 7 seconds per cue. The other presets are stricter or looser. Treat them as adjustable starting points; your platform or client may ask for different values.
Limits you should know
- Everything runs in your browser. Text you paste and files you choose are not uploaded to TubeTranscript or anywhere else.
- Presets are defaults, not rules of any platform. Check the requirements of where you publish.
- Auto-fix only changes cue order, overlapping end times and stray spaces. It does not shorten lines or rewrite text.
- Files are limited to 5 MB and are read as UTF-8.
FAQ
Is the SRT checker free?
Yes. There is no sign-up and no limit, because the check runs in your browser.
Does it work with VTT files?
Yes. WebVTT files, including ones without hours in the timestamps, are read the same way.
What does auto-fix change?
It sorts cues by start time, shortens a cue that overlaps the next one so it ends where the next begins, and removes extra spaces. Wording and line breaks stay as they are.
Why does it report a high reading speed?
The number of characters, without spaces, divided by the seconds the cue is on screen is above the preset. Shorten the text or show the cue longer.
Can I change the limits?
Choose another preset. Custom values are not available yet.
By Kenji Saito · Updated