Subtitle Sync Fixer
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Fix captions that do not line up with the audio. There are two different faults behind the same complaint, and they need different corrections: a constant offset, where the subtitles are the same few seconds out for the whole film, and gradual drift, where they start fine and are seconds adrift by the end. The second one is a frame-rate mismatch and no amount of shifting will fix it — the timings have to be rescaled. This tool does both, and returns the file in the format you gave it.
0 characters · runs entirely in your browser
How to use Subtitle Sync
- 1
Paste your subtitles, or drop in a .srt, .vtt or .ass file.
- 2
If they are consistently early or late, enter the offset in seconds — negative makes them appear sooner.
- 3
If the error grows over time, set the source and target frame rates instead.
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Frequently asked questions
My subtitles are a few seconds late the whole way through.+
That is a constant offset — the easy case. Note how far out they are, enter it as a negative number to pull them earlier or positive to push them later, and convert. Measure it at a line of dialogue you can hear clearly rather than guessing.
They start fine but drift further out as the film goes on.+
That is a frame-rate mismatch, not an offset, and shifting cannot fix it — correcting the start only moves the error to the end. It happens when subtitles timed for a 25 fps PAL release are played against a 23.976 fps release, or the reverse. Set both frame rates and every timing is rescaled proportionally.
Which frame rates should I choose?+
23.976 is the standard for film-sourced video, 25 for PAL/European broadcast, and 29.97 for NTSC. A drift of roughly four seconds per hour is the classic 25 to 23.976 signature. If you are unsure, the media player’s file information panel will show the video’s real rate.
Do I get the same format back?+
Yes. An SRT comes back as SRT, a WebVTT as WebVTT. Fixing sync is not a conversion, and handing back a different format would just create a second problem.
What happens to cues pushed before the start?+
A large negative offset can move early cues before 0:00, where they cannot be represented or displayed. Those are dropped and the count is reported, rather than being silently clamped into a pile of zero-length cues at the beginning.