Free tool · Nothing uploaded

Subtitle timing shifter

Subtitles that show up too early or too late are usually off by a fixed amount. Paste an SRT or WebVTT file, set how far to move it, and download a corrected copy in the same format. Everything runs in your browser.

Shift settings
Direction
Unit

Enter how far to move the subtitles.

Cues are counted from 1, in the order they appear in the file.

Paste the text, or drop a .srt or .vtt file here. Up to 5 MB.

Shifted subtitles

Saved in the same format as your file.

Paste subtitles or choose a file, and the shifted version appears here.

Runs in your browser. Nothing is uploaded.

How to use it

Fix subtitle sync in four steps.

No account and no upload. Close the tab and nothing is kept.

  1. Paste your subtitles, or drop a .srt or .vtt file onto the box.
  2. Choose Earlier if subtitles appear after the words are spoken, or Later if they appear before. Enter the amount in seconds or milliseconds.
  3. To fix only part of the file, enter the number of the first cue that is out of sync.
  4. Check the first shifted cue under the settings, then copy or download the file.

How to find the right offset

Play the video with the subtitles on and pick a line with a clear start, such as the first word after a pause. Note two times from your player: when the word is heard, and when the subtitle appears.

measuring the offset
Word is heard:      00:01:12.400
Subtitle appears:   00:01:14.000

Difference:         1.6 seconds late
Shift:              −1.6 s (Earlier)

A subtitle that appears after its words needs to move earlier by the difference; one that appears before them needs to move later. Before you download, check a second line near the end of the video. If it is off by the same amount, one shift fixes the whole file.

When one shift is not enough

If the subtitles are in sync at the start but drift further out as the video plays, they were probably timed for a different frame rate. For example, a video sped up from 23.976 to 25 frames per second runs about 4% faster, so subtitles made for the slower version fall further behind every minute. A constant shift cannot fix drift; the timings need to be stretched, which this tool does not do.

If the subtitles jump out of sync at one point, for example where a scene was cut or an ad break was removed, shift only from there. Find the first cue that is wrong, enter its number in Start from cue, and shift from that cue onward. Cues before it keep their timing.

What the shifter changes, and what it keeps

  • Only the times move. The text and formatting of every cue are kept, and SRT cues are numbered in order.
  • The format stays the same. An SRT comes back as SRT and a WebVTT file as WebVTT, with its header, STYLE and REGION blocks, cue identifiers and cue settings. NOTE comments are not kept.
  • Word-by-word timestamps move too. Timestamp tags such as <00:00:04.000> inside a WebVTT cue shift with the cue.
  • Nothing goes below zero. A cue that would start before 00:00:00 starts at zero instead, and the tool tells you how many cues that affected.
  • Times stay exact. Shifts are applied in whole milliseconds, the precision both formats store.

Need a different format as well? Convert with the SRT to VTT or VTT to SRT converter after shifting.

Questions

The short answers.

Which way do I shift?

If a subtitle appears after its words are spoken, shift earlier. If it appears before them, shift later. Typing a minus sign in front of the amount selects Earlier.

Can I shift only part of a file?

Yes. Enter a number in Start from cue, and only that cue and the ones after it move. Cues are counted from 1 in the order they appear in the file.

What happens to cues that would start before zero?

They are held at 00:00:00 rather than given a negative time, which neither format can store. The tool tells you how many cues that affected so you can check them.

Does it work with VTT files?

Yes. The shifter reads SRT and WebVTT and writes the result in the same format. A WebVTT file keeps its header, STYLE and REGION blocks, cue identifiers and cue settings.

Is my file uploaded?

No. The shift is calculated in your browser, and the file never leaves your device. There is no account to create.

My subtitles drift further out of sync as the video plays. Will a shift fix that?

Not on its own. Growing drift usually means the subtitles were timed for a different frame rate or a different cut of the video. You can line up one section at a time with Start from cue, but a full fix needs the timings stretched, which this tool does not do.

Keep going

From video to subtitles

Don't have subtitles yet? AutoCap generates them from your video.

Upload a video with English speech and get captions with a timing for every word. Edit any word, then export a burned-in MP4 rendered in your browser at up to 2K, or download SRT and VTT files on a paid plan. The free plan includes 2 minutes a month.

Generate subtitles Start free