AI Subtitle Studio
Free tool

Shift subtitle timing

Move every subtitle in a file earlier or later by the same offset — the fix for a track that's correct but consistently early or late. Free, no account, nothing kept afterward.

Nothing stored afterward No account needed SRT, WebVTT & ASS/SSA

Positive moves subtitles later, negative moves them earlier. Decimals are fine — -0.4 is a common correction. Nothing is ever pushed before the start of the file.

Your file is processed and sent straight back — never saved on our servers.

Prefer not to upload your file?

The AI Subtitle Studio desktop app has this same Tools section built in — plus AI transcription, translation and batch processing for a whole season at once, all running locally on your Mac or PC.

Get the desktop app
How it works

Three steps, no account

Upload your file

Drop in an SRT, WebVTT or ASS/SSA file — whichever it is, it's detected automatically.

Set the offset

Type how many seconds to move everything, or nudge it with the +/− buttons while you fine-tune.

Download the result

Get the file straight back in the same format, timings shifted and everything else untouched.

Working out the right offset

Find the offset before you shift

Play the video with the subtitles loaded and find a line whose exact moment you can identify. Note the time it should appear and the time it does, and subtract: if a line shows at 00:01:12.0 but is spoken at 00:01:14.5, the subtitles are 2.5 seconds early and the offset is +2.5.

Do this near the start and again near the end of the file. If the two answers agree, a single shift fixes the whole thing and this is the right tool. If the gap grows as the video goes on, the subtitles were made for a different framerate or cut, and no fixed offset will fix that — you'd need frame-by-frame audio sync, which is a desktop app feature.

Only timestamps change here. Text, formatting, and ASS styles and overrides are left exactly as they were — see our Tools documentation for the full byte-preservation guarantee this is built on.

FAQ

Questions about shifting timing

Which direction do I need?
If the subtitles appear before the words are spoken, they're early and you need a positive offset to push them later. If they lag behind the speech, use a negative one.
Can I shift by milliseconds?
Yes — the field takes decimals, so 0.25 is a quarter of a second. The nudge buttons move in halves and whole seconds for speed.
Do you keep my file?
No. It's processed in memory for this one request and never written to disk on our end.
The subtitles start right but drift further out as the film goes on.
That's a framerate or different-cut problem, not a fixed offset, and no shift here will fix it. The desktop app's Sync Subtitles feature re-times against the audio itself and handles drift.
Does it work on ASS files with styling?
Yes. Only the Start and End of each event are rewritten — styles, positioning, karaoke and typesetting are untouched.
I only need to shift part of the file, not all of it.
Use Shift a Section instead — it moves a chosen range of subtitles and leaves the rest alone.