Shift subtitle timestamps forward or back
Fix out-of-sync subtitles in seconds: enter an offset, drop your SRT or VTT file, and grab the corrected version.
Drop your .srt or .vtt file here
or click to browse
Runs entirely in your browser — your file is never uploaded to any server.
How it works
Enter the offset
Type the number of seconds to shift — positive to move forward, negative to move back.
Drop your file
Drag and drop your .srt or .vtt subtitle file. The shift is applied instantly in your browser.
Download the result
Click the download button to save the corrected subtitle file.
About subtitle timestamp shifting
Sync drift usually happens because the subtitle file was made for a slightly different cut of the video: a director's cut, a re-encode, anything with a different start offset. Every cue ends up early or late by the same fixed amount, start to finish.
A shift just adds a fixed offset, in seconds, to every cue. Subtitles running three seconds late? Enter -3. Two seconds early? Enter +2. You can go down to 0.1-second increments if you need that kind of precision. The spacing between cues doesn't change; only where each one starts and ends.
Runs entirely in your browser. Type the offset, drop the .srt or .vtt file, and the corrected version is ready almost instantly, same format in as out. Nothing is uploaded anywhere.
Frequently asked questions
- What does "shifting" do to my subtitle file?
- It adds a fixed number of seconds to the start and end of every cue. That fixes constant drift (subtitles uniformly early or late) without touching the spacing between cues.
- Does my file get uploaded to a server?
- No. The shift is calculated locally using the Web File API: your file is read by JavaScript in the browser and never leaves your machine. No account or connection needed once the page has loaded.
- Can I shift by a fraction of a second?
- Yes. Decimals like 1.5 or -0.25 work fine. Internally it's converted to milliseconds, so you don't lose precision.
- Does it work with VTT files as well as SRT?
- Yes. It reads the file extension to tell SRT (comma milliseconds) from VTT (dot milliseconds) apart, and outputs whichever format you fed it.
- What if only part of my subtitle file is out of sync?
- A constant shift won't help there: this tool assumes the drift is the same throughout. If subtitles start in sync but drift more toward the end, you need something like Aegisub (free, desktop), which can retime individual cues or apply a linear speed correction.
- Is there a limit on file size or number of cues?
- No enforced limit. These are small plain-text files, everything happens in browser memory, and even a file with thousands of cues shifts in under a second.
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