How to sync subtitles
- Drop your .srt or .vtt file in, or paste the subtitles.
- Play the video and note how far off the subtitles are. Enter that many seconds and choose Later if they appear too early, or Earlier if they appear too late.
- Save the shifted file and load it in your player.
Finding the right offset
Pick a clear line of dialogue near the start. Note the time it’s spoken in the video and the time its subtitle appears (the start time in the file). The difference is your shift. For example, if a line is spoken at 00:01:12.0 but the subtitle shows at 00:01:09.5, shift 2.5 seconds later.
Subtitles that drift gradually
If the subtitles are fine at the start but get further out of sync as the video plays, the timing was made for a different frame rate, usually 23.976 fps versus 25 fps (common with films and European TV). Choose the matching option under “Fix gradual drift”. You can combine it with a shift if the start is also off.
Good to know
- The file stays in its format: SRT stays SRT, VTT stays VTT. To change format, use the subtitle converter.
- Subtitles moved before 00:00:00 are removed, and the tool tells you how many.
- Most players also have a subtitle delay setting, but it resets each time. Fixing the file fixes it everywhere.
Worked example
You downloaded subtitles for a film, and every line appears about two seconds before the actor speaks. Enter 2, choose Later, and save. If the first scene is right but the last scene is a few seconds early, the problem is drift rather than a fixed offset: choose “Subtitles for 23.976 fps, video is 25 fps” (or the reverse) instead, and check a line near the end.
Keep a copy
The shifted file is saved with “_shifted” in its name, so your original stays untouched. If the result isn’t quite right, try again from the original rather than shifting the shifted file, so small errors don’t add up.
Questions
How do I fix subtitles that are out of sync?
Measure how far off they are, enter that many seconds, choose Later or Earlier, and save the corrected file.
Why do my subtitles drift over time?
They were timed for a different frame rate, often 23.976 versus 25 fps. Use the drift option to correct the speed.
Does it work with VTT files?
Yes. SRT and VTT both work, and the format is kept.
Are my files uploaded?
No. Everything happens in your browser.