How to fix out of sync subtitles
Subtitles go out of sync in one of two ways, and each needs a different fix.
- Every line is late (or early) by the same amount. The subtitle file was made for a release with a different intro, studio logo or edit. Shift all cues by a fixed number of seconds.
- The first lines are fine but they drift further off as the video goes on. The file was timed for a different frame rate, usually 25 fps (PAL) against 23.976 fps (film/NTSC). Shifting won’t fix it; the cues need stretching.
Shift subtitle timing by a fixed amount
- Drop or paste your .srt or .vtt file.
- Play the video and note one line: when it’s spoken, and when its subtitle appears.
- If the subtitle shows up 2.5 seconds after the speech, enter
-2.5. If it comes too early, use a positive number. Values go down to the millisecond. - Download the fixed file and load it in your player alongside the video.
Two-point sync for drift
When the gap grows over the video, pick Two-point sync. Find the time the first subtitle should start in your video, and the time the last one should start. The tool maps the first cue to the first time and the last cue to the second, and spaces every cue in between proportionally. This fixes a frame-rate mismatch and a different intro length together, and you don’t need to know either one.
Times can be typed as 01:32:10,500, 92:10.5 or plain seconds like 5530.5.
Frame rate conversion
If you know the frame rates, the Frame rate conversion mode multiplies every timestamp by the ratio. Common cases:
| Subtitles timed for | Video plays at | Multiply times by | Drift over 90 minutes |
|---|---|---|---|
| 25 fps | 23.976 fps | 1.04271 | about 3 min 50 s |
| 23.976 fps | 25 fps | 0.95904 | about 3 min 41 s |
| 24 fps | 23.976 fps | 1.00100 | about 5 s |
If the result is still off by a constant amount, run the output back through with a fixed shift.
What gets changed
Only the timestamps on the --> lines are rewritten. Cue numbers, text, italics tags and WebVTT cue settings like align:start stay exactly as they were, and an SRT stays an SRT (comma before the milliseconds) while a VTT keeps its dots. If a shift would push a cue before zero, it’s set to 00:00:00 and the tool tells you, so you can delete it.
FAQ
How do I shift subtitle timing in an SRT file?
Drop the .srt file here, enter how many seconds to move it (negative for earlier, positive for later), and download the result. Every timestamp moves by the same amount; the text and numbering stay the same.
Why do my subtitles drift further out of sync over time?
The file was timed for a different frame rate, most often 25 fps against 23.976 fps. A fixed shift can’t fix that. Use two-point sync with the correct start times of the first and last cue, or the frame rate conversion mode.
Should I enter a positive or negative number if subtitles appear too early?
Positive. If subtitles appear before the speech, they need to come later, so add time. If they appear after the speech, enter a negative number to make them earlier.
Can I fix VTT subtitles as well as SRT?
Yes. WebVTT files are detected from the WEBVTT header and kept as VTT, with dots before the milliseconds and any cue settings left in place.