Free browser utility
Subtitle Duration Calculator
Paste subtitles to inspect timing consistency and locate cues that are too short, too long or overlapping.
✓ Local processing✓ No registration✓ No file upload
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Before
Cue 1 ends at 00:05.000; cue 2 starts at 00:04.700
→
After
300 ms overlap detected
How to use Subtitle Duration Calculator
- Paste text or select local files in the tool area.
- Choose any options that match the source data.
- Run the conversion or repair and review the preview.
- Copy the result or download the generated file.
Privacy and local processing
This project performs processing, document generation or calculations in your browser. The page does not include an upload endpoint, analytics script or remote processing API call. Avoid pasting sensitive data into websites you do not control.
What this tool includes
- duration and gap analysis
- overlap detection
- coverage summary
Common uses
- timing QA
- subtitle synchronization
- caption delivery reports
Practical tips
- Very short cues can be difficult to read even when CPS looks acceptable.
Frequently asked questions
Does Subtitle Duration Calculator upload my data?
No. The included tool runs locally in your browser and does not send the entered content to a processing server.
Can I use the result commercially?
The generated result is based on your own input. Review it for accuracy and any third-party rights before commercial use.