Edit subtitles online
Edit subtitle text and timing cue by cue, next to your own video. Problems are flagged as you type. Nothing is uploaded and no account is needed.
Every other tool here applies one decision to a whole file — shift everything, clean everything, convert everything. Sooner or later the problem is narrower than that: one line is mistranslated, one cue sits half a second late, two lines belong together, a sentence got cut in the wrong place. That is the job a desktop subtitle editor exists for, and the reason people install one. Subtitle Doctor puts the same thing in a browser tab: a list of every cue with its text and timing, editable in place, with your own video playing alongside so you can click a line and jump straight to the moment it is spoken. Problems are marked while you work — overlaps, cues too fast to read, lines too long, cues with no duration — so the file gets checked as you edit rather than after you have already saved it.
Worth knowing
- Clicking a cue number jumps the video to that moment, which turns checking a suspicious line from a scrubbing exercise into a single click. The video is played from your disk and never uploaded, exactly like everywhere else on the site.
- Problems are flagged live, per cue, rather than in a report at the end: an overlap says how many milliseconds it overlaps by, and a reading-speed warning gives the actual characters-per-second figure.
- Splitting a cue divides its duration in proportion to the text on each side rather than simply halving it, so both halves end up with roughly the same reading speed instead of one being impossible.
- Undo covers everything, including timing edits, splits, merges and deletions, because every operation produces a whole new cue list and history is a stack of those — there are no hand-written inverse operations to get out of step.
- The shift buttons on a selected cue move that cue and every cue after it, which is the correct fix when a file drifts from one point onward rather than being wrong from the beginning.
- Timestamps commit when you leave the field or press Enter, not on every keystroke, so a half-typed time never becomes an edit you have to undo.
FAQ
Can I edit an .ass file and keep its styling?
No, and the editor says so when you open one. Subtitle Doctor keeps the original ASS file byte for byte and rewrites only the timing fields for shift and sync, which is how styles, karaoke and positioning survive those operations. Editing the dialogue itself cannot be written back the same way, so an edited ASS file is saved in a plain format. If you only need timing changes on an ASS file, use the shift or sync tools instead.
How many cues can it handle?
A feature film is a few thousand cues and that is comfortable. Everything runs locally in your browser, so there is no upload, no per-file limit and no queue — the practical ceiling is your own machine rather than a plan tier.
What counts as a problem worth flagging?
Anything that makes the file invalid or unreadable: a cue that ends before it starts, a cue with no text, a cue still on screen when the next one begins, a line moving faster than about 21 characters per second, a line over 42 characters, or more than two lines at once. The first three break playback; the rest are the readability guidelines professional subtitlers work to.
Do my edits get saved automatically?
No. Nothing is stored anywhere, including in your browser, so closing the tab loses the work — download the file when you are done. That is the direct consequence of the no-server design that also means your subtitles are never uploaded to anyone.