Boneyard Tools

Subtitle Time Shifter

When subtitles run ahead of or behind the audio, the fix is the same for the whole file: nudge every timestamp by the same amount. Drop an SRT or VTT file here, enter how many seconds (or milliseconds) to delay or advance, and download a corrected copy. The cue numbers, arrows, and caption text are left exactly as they were, and the file is processed entirely in your browser, so it is never uploaded.

How to shift subtitle timing

  1. Drag an SRT or VTT file onto the box, or click to browse for one.
  2. Enter the offset: positive to delay subtitles, negative to advance them.
  3. Preview the shifted timings, then download the corrected file.

Examples

Subtitles appear half a second too early

movie.srt with an offset of +0.5 seconds
Every cue moved 500 ms later, e.g. 00:00:01,000 becomes 00:00:01,500

Frequently asked questions

Is my subtitle file uploaded anywhere?

No. The file is read and rewritten entirely in your browser using JavaScript. Nothing is sent to a server, so your file stays on your device.

How does the shift work?

Every timestamp in the file is moved by the same amount. A positive offset delays the subtitles (pushes them later) and a negative offset advances them (pulls them earlier). Cue numbers, the arrows between times, and the caption text are left untouched.

Does it support both SRT and VTT files?

Yes. SRT uses a comma before the milliseconds (00:00:01,000) and VTT uses a dot (00:00:01.000). Each timestamp keeps its own separator, and the download uses the same extension as the file you dropped in.

What happens if a shift would make a time negative?

Times are clamped at zero, so a cue can never go before the start of the file. If you advance by more than a cue's current time, that timestamp becomes 00:00:00,000 and later cues shift normally.

Will it change anything other than the timestamps?

No. Only text that matches a full HH:MM:SS timestamp is changed. Numbers in the caption text, chapter labels, and the WEBVTT header are all preserved exactly.

Can I shift by milliseconds, not just whole seconds?

Yes. You can switch the offset unit between seconds and milliseconds. Subtitle timing is millisecond-accurate, which is useful for small nudges of a tenth of a second or so.

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