How to shift only part of a subtitle file
TL;DR — Shift one selected time range inside an SRT, VTT, ASS, or SSA subtitle file while keeping the rest of the captions unchanged.
Related tool
Partial Subtitle Shifter
Use a partial shift when only one section is wrong and the rest of the subtitle file is already synced. This is common after a scene cut, trimmed intro, inserted ad break, or edited middle section.
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. The tool runs locally in your browser and supports SRT, VTT, ASS, and SSA input.
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.
If the subtitle issue starts right after a video edit, use the same workflow from fix subtitle sync after a scene cut to choose the range start and direction.
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.
For example, if your range starts at 00:05:00,000, a cue that starts at 00:04:58,000 and ends at 00:05:02,000 stays unchanged. Start the range at the first cue that should actually move.
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.
Frequently asked questions
Can I shift only one section of an SRT file?
Yes. Set the start and end timestamps for the affected section, then apply the offset only to that range. Captions outside the range keep their original timing.
What happens to subtitles outside the selected range?
They stay unchanged. That is the main reason to use a partial shift instead of a full-file timing shift.
Should I use a partial shift after a scene cut?
Yes, when sync is correct before the cut and wrong afterward. Use the first out-of-sync cue as the range start.
Can I use negative milliseconds for a partial shift?
Yes. Negative values move selected cues earlier; positive values delay selected cues.
Related guides
Related tools
Use the Partial Subtitle Shifter
Shift one selected SRT, VTT, ASS, or SSA subtitle range without moving the rest of the captions. No signup, no upload, and everything runs locally in the browser.
Open Partial shifter