Sync Subtitles Online: Shift SRT and VTT Timing
Shift all or selected subtitle lines forward or backward. Change start or end times, preview changes and export SRT or VTT.
How to Use Subtitle Sync
- Import subtitles and select the affected lines
- Set the offset and which timestamps to change
- Apply, review warnings and export; undo is available
Supported Formats and Limitations
Positive values delay subtitles; negative values make them appear earlier. Calculations use integer milliseconds.
Negative or reversed timestamps are rejected. Potentially valid overlaps are only flagged.
This is manual timing correction, not automatic audio alignment. Progressive drift may require separate adjustments.
Example input and output
This example delays both timestamps by 0.5 seconds.
1 00:00:01,000 --> 00:00:04,200 The coast reminds us to slow down.
1 00:00:01,500 --> 00:00:04,700 The coast reminds us to slow down.
Frequently Asked Questions
Do I need to upload my files or sign in?
No. This free tool processes your files locally in your browser without an account. Export your result before leaving the page.
What should I check before downloading?
Positive values delay subtitles; negative values make them appear earlier. Calculations use integer milliseconds.
Will my original file be changed?
The source file is not overwritten. Review the result and download a new file. Keep your original when converting formats, because styling and positioning may not carry over.