How to fix subtitles that are out of sync
Shift SRT or VTT subtitles earlier or later with the correct offset. Learn the difference between a constant subtitle delay and gradual timing drift.
Free subtitle tool
Subtitle Frame Rate Converter
Retime SRT or VTT subtitles for a known frame rate change, including 23.976, 24, 25 and 29.97 fps. Correct consistent timing drift.
About Subtitle Frame Rate Converter
Use this tool when the same video content plays at a different frame rate and its duration changes. For example, a 24 fps master played at 25 fps finishes sooner; subtitle times must shrink by 24/25. This differs from a fixed caption delay, which the time shifter corrects.
What to expect
- New time = original time × source frame rate ÷ target frame rate. Zero is the timing anchor.
- 23.976, 29.97 and 59.94 use the exact ratios 24000/1001, 30000/1001 and 60000/1001. Output is rounded to milliseconds.
- SRT/VTT do not declare a playback frame rate. Use the rates of your source and destination video versions.
- Re-encoding at a different fps while preserving duration needs no retiming. Edits, missing scenes and variable drift require manual synchronization.
How to use Subtitle Frame Rate Converter
- 01
Load the original subtitles
Open a caption file timed for the source video version.
- 02
Set both frame rates
Choose the source and target playback rates. Check the displayed scale and explanation before applying it.
- 03
Check the beginning and end
Preview and download the result. Test captions near the beginning and end of the target video to confirm synchronization.
Frequently asked questions
Should I use this or the time shifter?
Use the time shifter if all captions are early or late by the same amount. Use frame rate conversion only when a known playback-rate difference causes the delay to grow over time.
Will this change my video frame rate?
No. It changes subtitle timestamps only. The video and its playback speed remain unchanged.
Why is changing from 24 to 25 fps a 0.96 multiplier?
The same frames play in less time at 25 fps. Multiplying subtitle times by 24/25 places them at the corresponding positions in that faster version.
Subtitle guides
View all guidesUnderstand the formats, follow an example, and choose your next step.
How to merge and split subtitles for edited videos
Combine caption files with explicit time offsets or split SRT and VTT at a video cut. Includes examples for silence, crossing captions and timeline resets.