Subtitle time shift
Open SRT or VTT captions that are out of sync. Shift them earlier or later, fix subtitles that drift further off as the video plays, or pin two captions to the right times and let the rest follow.
- Free, no sign-up
- Your file never leaves your browser
- Exact to the millisecond
Offset or drift: which one you have
- Offset
- Off by the same amountShift by a time or a number of frames
- Drift
- Later and laterA frame-rate mismatch: rescale, or sync on two points
- 23.976 → 25 fps
- × 0.95904About 2.5 minutes over an hour
- Before 0:00
- Clamped to 00:00:00,000And counted, so you can check them
How to tell
Play the video at the start and again near the end. If the subtitles are off by the same amount both times, that is an offset: one shift fixes it. If they are close at the start and further off later, the subtitles were timed for a different frame rate, typically a 23.976 fps film played as a 25 fps copy, which runs about 4% faster. A shift can't fix drift. Pick the two frame rates under “Frame rate”, or use two-point sync when you don't know them: set the right time for a caption near the start and one near the end, and every caption in between is placed on the line between those two.
Exact to the millisecond
The shifter works in whole milliseconds, the precision both formats store, so shifting by 1.5 seconds and back returns the original file. A shift in frames is converted at your frame rate and rounded to the nearest millisecond. SubRip writes 00:00:01,000 and WebVTT 00:00:01.000; the shifter keeps the format you opened unless you choose the other one.
Need to change words or split a long caption as well? Open the file in the SRT editor. To swap formats without retiming, use the SRT to VTT converter.
Sources: Library of Congress: SubRip Subtitle format (SRT) · W3C: WebVTT, the Web Video Text Tracks Format (Candidate Recommendation Draft, May 20, 2026), read on October 28, 2026.
Embed this tool
Teachers, bloggers and course creators can put this subtitle time shift on their own page for free. Paste the code below into your page's HTML. It loads from markstudios.com, so it stays current when we update the numbers.
Questions, answered.
Anything else? Message Mark and you'll get a written reply within one business day.
How do I shift subtitles that are all early or late by the same amount?
Open the file, choose “Shift by”, pick Later or Earlier and type the amount: seconds (1.5), a time (0:02.250) or a number of frames at your frame rate. Every caption moves by exactly that much, to the millisecond, and you download the fixed .srt or .vtt.
Why do my subtitles get later and later as the video plays?
That is drift, not an offset: the subtitles were timed for a video at a different frame rate. Subtitles timed for a 23.976 fps film fall about 4% behind on a 25 fps copy, which is roughly 2.5 minutes by the end of an hour. Shifting can’t fix it; choose “Frame rate” and pick the two rates, or use two-point sync.
How does two-point sync work?
Pick one caption near the start and one near the end and type when each should appear. Every other caption is placed on the straight line between those two, so an offset and a drift are fixed in one go, even when you don’t know either frame rate.
Can I shift only part of a subtitle file?
Yes. “From caption” leaves every caption before that number where it is and moves the rest, which fixes a file that went out of sync after a cut or an ad break.
What happens to a caption that would start before 0:00?
Its times are set to 00:00:00,000 and the page says how many captions that happened to, so you can check them before you upload the file.
Does shifting change the text or the formatting?
No. Only the times change. The text, line breaks, tags and caption numbers stay as they were, and so do WebVTT cue names, settings and NOTE blocks when you keep the same format.
Rather have captions timed for you?
Mark can add captions to your videos, burned in or as SRT files, priced in the instant quote, and you work directly with Mark.
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