Tools Guides Use Tools →
Subtitle utility

Subtitle Delay Fixer

Fix out-of-sync subtitles by shifting SRT, VTT, or ASS captions earlier or later in milliseconds.

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.

Fixed subtitle output

Runs locally in your browser

Selected file: sample.srt

Workflow notes

How to use this Delay fixer tool

Use this when subtitles are consistently ahead of audio, behind speech, or out of sync by the same amount. Enter positive milliseconds to delay captions, enter negative milliseconds to move captions earlier, then review the first and last cues before replacing the original file.

  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 Delay fixer 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

  • Applying a global delay fix to subtitles that drift gradually over time.
  • Entering seconds when the tool expects milliseconds.
  • Using the wrong sign for captions ahead of or behind audio.

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 delay fixer when every caption is ahead of audio, behind speech, or out of sync by the same number of milliseconds.

  • Fix subtitles that appear ahead of audio or behind speech by a constant offset.
  • Delay captions by entering a positive millisecond value after a video intro was added.
  • Move all subtitle cues earlier with a negative millisecond value after trimming a video start.
  • Repair out-of-sync SRT, VTT, ASS, or SSA files without opening a video editor.

FAQ

Is this subtitle delay fixer free? +

Yes. You can fix subtitle delay for free in your browser without signup.

Should I use a positive or negative value? +

Use a positive value when subtitles are ahead of audio. Use a negative value when subtitles are behind speech.

How many milliseconds should I shift subtitles? +

Estimate the offset between the spoken audio and the matching caption. For example, use 1500 to delay subtitles by 1.5 seconds, or -1500 to move them 1.5 seconds earlier.

Can this fix out-of-sync subtitles? +

Yes, when the whole subtitle file is off by a constant amount. If only one section drifts out of sync, use the partial subtitle shifter instead.

Can this fix subtitles ahead of audio? +

Yes. If every caption appears before the matching speech by the same amount, enter a positive millisecond value to move captions later.

Can this fix subtitles behind audio? +

Yes. If every caption appears after the matching speech by the same amount, enter a negative millisecond value to move captions earlier.

Does this preserve the subtitle format? +

Yes. SRT stays SRT, VTT stays VTT, and ASS stays ASS after the delay fix.

Are my subtitle files uploaded to a server? +

No. The delay fix runs locally in your browser, so your subtitle file stays on your device.