How to Resync Subtitles
Use this subtitle shifter when every caption is off by roughly the same amount. It moves all cue times together, keeping the text and file format. File reading, adjustment and download run locally in your browser.
Choose SRT or VTT
Select one UTF-8 subtitle file, with or without a BOM, up to 5 MB. Check its cue preview. You do not need to upload a video or create an account.
Set the direction and amount
Choose Advance (−) for earlier subtitles or Delay (+) for later ones. Enter a positive Amount and select Seconds or Milliseconds. Presets fill these controls for common shifts; check the direction before applying one.
Compare and download
Select Shift subtitles, then compare Before and After times. Read any input notes before downloading the complete result in its original format. Reset clears the workspace for another file.
Should You Shift Subtitles Earlier or Later?
| What you see | Choose | Example |
|---|---|---|
| Subtitles too late | Advance (−), earlier | 2 seconds late → −2s |
| Subtitles too early | Delay (+), later | 2 seconds early → +2s |
One second equals 1,000 milliseconds. An amount of 2.5 Seconds and 2500 Milliseconds produce the same shift when the direction is the same. Seconds accept up to three decimal places; milliseconds use whole numbers.
Subtitle Shifter Example
Choose Advance (−), Amount 2, Seconds to move this cue two seconds earlier. The same offset is applied to every cue in the file, not just the first one.
1 00:00:05,000 --> 00:00:08,000 Hello world.
1 00:00:03,000 --> 00:00:06,000 Hello world.
SRT and VTT Subtitle Timing
SRT stays SRT; VTT stays VTT. This page changes cue start and end times rather than converting formats. Cue text and order stay the same. Durations stay the same unless a time is clamped at zero.
Supported WebVTT settings and metadata are retained. Inline timing tags and timestamp maps stay as written, with notes that they are not adjusted. Review advanced WebVTT files before relying on the shifted result.
Manual Shift vs Automatic Subtitle Sync
A fixed shift fits one consistent timing error. If the error grows or changes as playback progresses, one offset will not fully synchronize the subtitles. You may need individual cue edits or a separate alignment workflow.
| Capability | This shifter | Automatic alignment tools |
|---|---|---|
| Choose the offset | You enter it | May estimate it |
| Move every cue equally | Yes | Depends on the tool |
| Correct changing drift | No | Depends on the method |
| Analyze media | No | May use media analysis |
| Local processing | Yes | Depends on the service |
The comparison describes different approaches, not another mode available here. The current subtitle resync workflow always uses the single offset you supply.
FAQ
How do I fix subtitles that are delayed?
If captions appear consistently late, choose Advance (−) and enter how late they are. For a two-second delay, use Amount 2 and Seconds. Shift the file, check Before and After, then review the download during playback.
What is a subtitle shifter?
A subtitle time shifter adds the same offset to every cue. It is suitable when the whole subtitle track is early or late by a consistent amount. You choose the offset; the tool does not discover it.
Should I use a positive or negative subtitle offset?
Positive means later: Delay (+). Negative means earlier: Advance (−). In this workspace, select the direction and enter a positive amount. Do not type a minus sign into Amount to select Advance.
Can I resync SRT files?
Yes. An SRT time shift keeps the output as SRT, with comma-separated milliseconds. Cue text and order remain unchanged. Check the new times before downloading, especially when advancing cues close to the start.
Can I resync VTT files?
Yes. VTT input stays VTT, with supported cue IDs, settings and metadata retained. Advanced inline timestamps and timestamp maps are not recalculated. These inputs receive notes and may need manual review.
Does this permanently change the subtitle file?
It creates a downloadable file with updated timestamps. It does not overwrite your original local file. Keep the source if you want to try another offset or compare the result later.
Is this automatic subtitle synchronization?
No. This tool applies the offset you choose. It does not detect speech, inspect a video or find the best delay automatically. Use it when you already know how far the cues should move.
Can this fix subtitles that drift further out of sync over time?
No. One global offset cannot fully correct a delay that changes throughout playback. Check a few points near the beginning and end; different errors require more than an equal shift of all cues.
Can I fix subtitle delay in VLC instead?
A player delay adjustment changes timing during playback. This tool instead saves updated cue timestamps in a separate subtitle file, so you can use that file in another compatible player or workflow.
What happens if shifting makes a timestamp negative?
Each start or end time below zero is clamped to zero, with an input note for every affected cue. Advancing a cue from 1–2 seconds by 3 seconds makes both times zero. Clamping can shorten a cue or give it zero duration; review those cues before use.