Subtitle Editor
Processed locally in your browser — nothing is uploaded.
Quick answer
A subtitle editor lets you fix the actual words and timing of individual captions. This one loads any SRT, VTT or ASS file into an editable table where each row is one cue — change the text, adjust the start and end times, insert or delete lines — then export back to SRT, VTT or ASS. Everything runs in your browser, so even long or confidential caption files never leave your device.
How to subtitle editor
Open a subtitle file
Drag in an .srt, .vtt or .ass file, or paste subtitle text. Each cue loads as a row you can edit.
Edit cues in the table
Click any text field to fix wording, or the time fields to retime a cue. Add a new cue or delete one with the row controls.
Export your edited subtitles
Choose SRT, VTT or ASS and download the result, or copy it to the clipboard. The cues are renumbered automatically.
What can you fix in the subtitle editor?
The editor is for the changes a bulk shift or a converter cannot make — the ones that need a human eye on individual lines:
- Correcting typos, mishearings and auto-caption mistakes.
- Retiming a single cue that lingers too long or flashes by too fast.
- Splitting an over-long two-line cue into two, or merging two short ones.
- Deleting junk cues — sound-effect noise, watermark lines, duplicate credits.
- Adjusting reading speed by extending a cue’s end time.
What timing should each caption follow?
Professional subtitling follows a few readability rules worth knowing while you edit. They keep captions comfortable to read rather than a race:
| Guideline | Typical value | Why it matters |
|---|---|---|
| Reading speed | ≤ 17–20 characters/second | Faster than this and viewers cannot finish reading |
| Minimum duration | ≈ 0.8–1 second | Below this the eye cannot land on the text |
| Maximum duration | ≈ 7 seconds | A caption lingering longer reads as stuck |
| Line length | ≤ 42 characters | Longer lines wrap awkwardly on small screens |
| Gap between cues | ≥ 2 frames (~40 ms) | Prevents flicker between consecutive captions |
To audit a whole file against these automatically rather than eyeballing each row, use the timing checker, which flags every cue that reads too fast, sits on screen too briefly, or overlaps its neighbour.
Which format should you export to?
Export SRT for the widest compatibility (VLC, YouTube, editing software), VTT if the captions are headed for an HTML5 web player, or ASS if you need to preserve or add styling and positioning. The editor renumbers cues on export, so deletions and insertions never leave gaps in the numbering.
Are my captions uploaded while I edit?
No. The entire editor is client-side: the file is parsed into memory, you edit the in-memory cues, and the export is built in your browser. Nothing is transmitted at any point — confirm it in DevTools → Network. That makes the editor safe for unreleased scripts and private recordings.
Related subtitle tools
To move every cue by the same amount instead of editing individually, use the subtitle shifter. To change only the format, use the subtitle converter. When your edit is finished, add the subtitles to your video to ship a captioned file.
Your files never leave your device
Processed locally in your browser — nothing is uploaded. You can verify it yourself: open your browser’s developer tools, watch the Network tab, and use the tool — no upload request is ever made.
Frequently asked questions
Can I edit an SRT file without downloading software?
Yes. This editor runs in the browser. Load the .srt, edit cues in the table, and export — no install and no upload.
Will editing change the timing of other cues?
No. Editing one cue’s text or time affects only that cue. Other cues keep their timing unless you change them.
Can I add a brand-new caption?
Yes. Insert a row, type the text, and set its start and end times. On export the file is renumbered so the new cue fits in sequence.
Does the editor keep my ASS styling?
Cue text and per-cue style names are preserved through an ASS round-trip. Editing text does not remove the style; converting to SRT would.
How do I fix a caption that reads too fast?
Extend its end time (or shorten the text). Aim for under about 20 characters per second. The timing checker can flag which cues exceed that.
Is there a limit on how many cues I can edit?
No practical limit. Because it is all local, even a feature-length file with thousands of cues edits smoothly with no server quota.
Can I undo a deletion?
Re-import the original file to start over. Since nothing is uploaded, your source file on disk is always your safety net.