How to fix out-of-sync subtitles
- Drop your
.srtor.vttfile into the box above, or paste the subtitle text. - Play your video and note how far off the subtitles are. If a line appears 2 seconds too late, enter
-2.
If it appears too early, enter a positive number such as 1.5.
- Press Apply, check the first few lines of the result, then press Download.
Times are accurate to the millisecond, so 0.25 moves every subtitle by a quarter of a second.
Three ways to sync
Shift all times. Use this when every line is off by the same amount, for example when a video has an extra intro or the subtitles were made for a version with a different opening.
Make the first subtitle start at a time. If you know exactly when the first spoken line begins, type that time (for example 00:00:12,500) and every subtitle moves by the same amount. This is the fastest method when you can find the first line in your video editor.
Fix frame-rate drift. If the subtitles start in sync but slowly drift further away, the file was probably timed for a video with a different frame rate. A typical case is subtitles made for a 25 fps European broadcast used on a 23.976 fps film release: by the end of a 90-minute film they are almost four minutes off. Choose the frame rate the subtitles were made for and the frame rate of your video, and every time is stretched or squeezed to match.
| Drift you see | Likely fix |
|---|---|
| Same delay from start to end | Shift all times |
| Correct at the start, later and later towards the end | 25 → 23.976 |
| Correct at the start, earlier and earlier towards the end | 23.976 → 25 |
Fixing only part of a file
If the subtitles are right until an ad break or a cut scene and wrong after it, set Start from subtitle number to the first line that is wrong. Lines before it stay exactly as they were.
SRT and VTT
SRT (SubRip) is the format most video players and editors read. WebVTT (.vtt) is the format for web video players, HTML5 <track> elements and many online course platforms. They hold the same timing and text; VTT uses a dot before the milliseconds instead of a comma, starts with a WEBVTT line and does not need line numbers. Choose the format under Save as and the tool converts while it shifts, so you can also use it as a plain SRT to VTT converter with a shift of 0.
YouTube accepts both formats when you upload captions in YouTube Studio.
Good to know
- If a shift would move a line before 0:00, that line is set to 0:00 and the tool tells you how many lines it changed.
- The tool warns you when lines overlap, which some players show as two lines at once.
- Text, line breaks and simple formatting tags such as
<i>are kept as they are. - WebVTT position settings (like
align:start) are kept when you save as VTT and removed for SRT, which does not
support them.
FAQ
Is my file uploaded anywhere? No. Everything happens in your browser, so it also works for unreleased videos.
Can it fix subtitles that are wrong in different places by different amounts? Run the tool once per section using Start from subtitle number, starting with the earliest section.
Why does my player still show the old timing? Many players cache subtitles. Rename the downloaded file to match your video file name and reload the video.