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Subtitle utility

Subtitle Time Shifter

Shift subtitle timing online for SRT, VTT, and ASS files. Move captions earlier or later in milliseconds locally with no upload.

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.

Shifted subtitle output

Runs locally in your browser

Selected file: sample.srt

Workflow notes

How to use this Time shifter tool

Use a global time shift when every subtitle cue is early or late by the same amount. Enter a millisecond offset, use positive values to delay captions, use negative values to move subtitles earlier, and export the shifted SRT, VTT, or ASS file locally with no upload.

  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 Time 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

  • Using a global shift when only one section is out of sync.
  • Entering seconds when the tool expects milliseconds.
  • Applying the wrong sign: positive delays captions, negative moves them earlier.

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 free subtitle time shifter when every cue is too early or too late by the same offset and you need a local SRT, VTT, or ASS timing fix.

  • Shift a whole subtitle file earlier or later in milliseconds.
  • Fix subtitle delay without opening a video editor.
  • Fix subtitles that lag behind the speaker.
  • Repair captions after editing the intro of a video.
  • Create a shifted SRT, VTT, or ASS copy while keeping the original format.

FAQ

Can I shift subtitle timing online for free? +

Yes. You can shift SRT, VTT, and ASS subtitle timing for free in your browser without signup or upload.

Should I use positive or negative milliseconds? +

Use positive milliseconds when subtitles appear too early and need to be delayed. Use negative milliseconds when subtitles appear too late and need to move earlier.

Will this preserve SRT, VTT, or ASS format? +

Yes. SRT stays SRT, VTT stays VTT, and ASS stays ASS after the shift.

Should I use this for one bad section? +

Use this tool when the whole subtitle file has the same timing offset. If only one section is wrong after an edit, use the partial subtitle shifter instead.

Are my subtitle files uploaded to a server? +

No. Timing changes run locally in your browser, so your subtitle file stays on your device.