Subtitle Time Shifter

Fix subtitles that don’t match the video

Few things are more distracting than subtitles that appear a second before or after the words are spoken. It usually happens when subtitles were made for a different cut of a video: one with a longer intro, an extra logo, a removed scene, or a different frame rate. This tool corrects the timing of SRT and WebVTT files in your browser, whether the problem is a simple delay or a gradual drift.

Method 1: shift all times

Use this when the subtitles are off by the same amount all the way through.

1. Open or paste your subtitle file.
2. Play the video and note a line of dialogue: when it’s actually spoken, and when its subtitle appears.
3. Enter the difference in seconds or milliseconds.
4. Choose “Later” if subtitles show up too early, or “Earlier” if they show up too late.
5. Optionally start from a later cue if only part of the file is out of sync, then download the result.

Method 2: sync with two points

If the subtitles start in sync but slowly drift — say, half a second off after 20 minutes and two seconds off by the end — a single shift can’t fix it. The cause is usually a frame-rate mismatch, such as subtitles timed for a 25 fps European release played with a 23.976 fps video.

1. Choose “Sync with two points”.
2. Pick a cue near the start and enter the time it should actually appear, for example 00:00:12,300.
3. Pick a cue near the end (the last cue is selected by default) and enter its correct time.
4. The tool calculates a speed factor and an offset and applies them to every cue.

Mathematically, each new time is old time × speed + offset, where the speed and offset are chosen so both reference cues land exactly where you said. Choosing cues far apart gives the most accurate result.

Finding the right timings

• Use a video player that shows milliseconds, such as VLC or MPV, and pause on the first frame of a spoken line.
• Pick distinctive lines — a name, a shout, or the first line after a long silence — so it’s easy to match them.
• In VLC you can test an offset first with the subtitle delay keys (G and H), then apply that value here to fix the file permanently.

What the tool keeps and changes

Only timestamps change. Cue text, line breaks, styling tags, VTT cue settings and headers are kept, and the file stays in its original format. If a shift would move a cue before 0:00:00, it’s set to zero and you’ll see how many were affected. Everything runs on your device — your files aren’t uploaded.

Need a different format as well? Convert with the SRT ↔ VTT Subtitle Converter. Working from an edit decision list? The Timecode Calculator converts between timecode and frames, and Video to MP4 makes your video play everywhere.