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Subtitle utility

Partial Subtitle Shifter

Shift one selected SRT, VTT, ASS, or SSA subtitle range without moving the rest of the captions.

Free No signup Browser-local

Subtitle input

No signup. No server upload. Browser-only processing.

Drop a subtitle file here or choose one manually

Supports SRT, VTT, and ASS where relevant to the tool.

Selected file: sample.srt

Use positive numbers to delay captions and negative numbers to move them earlier.

Use SRT-style timestamps such as 00:01:20,000. Only cues starting inside this range are shifted.

Partially shifted subtitle output

Runs locally in your browser

Selected file: sample.srt

Workflow notes

How to use this Partial shifter tool

Use a partial shift when only one scene, cut, or middle section changed after an edit. Choose the affected start and end timestamps, enter the millisecond offset, and keep every cue outside that selected range unchanged.

  1. Add a supported subtitle file. Upload or paste a supported subtitle file (.srt, .vtt, .ass, .ssa, .txt), or load the sample input to see the expected structure.
  2. Run the Partial shifter tool. Use the browser-based converter or repair action to process the subtitle file locally on your device.
  3. Review and download the output. Check the first few cues, the middle of the file, and the final cue before copying or downloading the result.

Input and output checklist

  • Use a complete subtitle file with valid cue timing when possible.
  • Keep a copy of the original file before replacing it in your workflow.
  • Review the first few cues, the middle of the file, and the final cue after export.
  • Test the downloaded output in the destination player, editor, or upload form.

Common mistakes to avoid

  • Setting a range that does not include the cue start times you want to move.
  • Using a partial shift when the whole file is offset by the same amount.
  • Forgetting to review the cue just before and after the edited section.

All processing runs in your browser, so the subtitle or video file does not need to be uploaded to a server. That is useful for client review files, unreleased videos, internal training material, and other caption workflows where the text should stay on your device.

When to use this tool

Use this when only one scene, cut, or edited segment is out of sync, while the rest of the subtitle file already matches the video.

  • Fix sync after a scene cut without moving the whole file.
  • Repair a middle section that drifts while the intro and ending are correct.
  • Move a selected SRT, VTT, ASS, or SSA subtitle range earlier or later before final review.

FAQ

Which cues are shifted? +

The tool shifts cues whose start time falls inside the selected start and end range.

Can I use a negative shift? +

Yes. Negative milliseconds move the selected cues earlier; positive milliseconds delay them.

Will cues outside the range change? +

No. Cues outside the selected range keep their original timing.

Should I use this after a scene cut? +

Yes, use a partial shift when subtitles are synced before a cut but become early or late after that edit point.