How to use
- Open a video (optional) and an existing subtitle file, or start from scratch.
- Press Add cue at playhead, type the text, and adjust start and end (type a time, use the arrow keys, or set it from the playhead).
- Split, merge or delete cues; use Shift and Stretch to fix sync across the whole file; check the warnings, then export.
Worked example
Shifting every cue by −1.250 s moves “00:00:05,000 --> 00:00:07,500” to “00:00:03,750 --> 00:00:06,250”.
Supported formats and limits
| Input | Video (MP4, WebM, MOV), SRT, VTT, ASS/SSA, SBV, TTML, JSON |
|---|---|
| Output | SRT, VTT, ASS, SSA, SBV, TTML, JSON, TXT |
| Engine | Subtitle parser/serializer with millisecond timestamps; HTML video with a live caption overlay |
Limitations
- Styling from ASS files (fonts, positions) is not preserved; italic, bold and underline are.
- The draft is kept in this browser's storage until you clear it; the video is not stored.
- No waveform view; time cues against the video picture.
Questions
How do I fix subtitles that are consistently early or late?
Use Shift all cues by with a positive or negative time. Shifting by minus 1.250 s moves 00:00:05,000 to 00:00:03,750. If the drift grows over the video, set when the first and last cues should start and every cue in between is stretched to match.
Is my video uploaded?
No. The video only plays in the page for timing. The subtitle draft is kept in this browser's storage until you clear it; the video is not stored.
Guides
Privacy
Runs on your device. Files and text are processed in this browser tab and are not uploaded.
See the privacy policy for how toolsdocks handles data.