How to shift only part of a subtitle file
TL;DR — Shift one selected time range inside an SRT, VTT, or ASS subtitle file while keeping the rest of the captions unchanged.
Use a partial shift when only one section is wrong and the rest of the subtitle file is already synced.
Quick answer
Open the Partial Subtitle Shifter, enter the start and end time of the bad section, enter the offset in milliseconds, then download the updated file.
Example
Original cue:
2
00:00:04,200 --> 00:00:06,000
Today we are fixing captions locally.If only cues from 00:00:01,000 to 00:00:05,000 need to move 1200 ms later, the output becomes:
2
00:00:05,400 --> 00:00:07,200
Today we are fixing captions locally.Cues outside that range stay unchanged.
Step-by-step workflow
- Find the first cue in the bad section.
- Find the last cue in the bad section.
- Open the Partial Subtitle Shifter.
- Enter the range start and range end using
00:00:00,000format. - Enter a positive offset to delay captions or a negative offset to move them earlier.
- Check the output around the range boundary.
How the range works
The tool shifts cues whose start time falls inside the selected range. A cue that starts before the range but ends inside it is left unchanged.
This behavior is useful because it avoids moving long captions that begin before the edited section.
Common mistakes
Using seconds instead of milliseconds
1200 means 1.2 seconds. 12 means 0.012 seconds.
Setting the range too wide
If you include already-correct cues, they will move too. Start with a tight range and expand only if needed.
Forgetting the boundary check
Always inspect the cue before the shifted section and the cue after it. Those two points reveal most partial-shift errors.
Related guides
Use the Partial Subtitle Shifter
Shift only a selected time range inside an SRT, VTT, or ASS subtitle file. No signup, no upload, and everything runs locally in the browser.
Open Partial shifter