Subtitle time shift: fix out-of-sync subtitles
Fix out-of-sync subtitles by shifting every caption earlier or later by the same amount. Works with SRT, VTT, ASS and SBV, and keeps the original format.
The conversion runs in your browser. Your file is not uploaded.
What the subtitle time shift tool does
The subtitle time shift tool moves all captions in a subtitle file by an offset you choose, to the millisecond. Use it to sync subtitles that appear too early or too late because the video has a different intro, was trimmed, or comes from another release. The shifted file is saved in the format you dropped in, and nothing is uploaded.
How to find the offset for out-of-sync subtitles
- Play the video and note when the first line is actually spoken — say 00:00:05.2.
- Look at the first caption’s start time in the file — say 00:00:03.0.
- The difference is your shift: 5.2 − 3.0 = 2.2 seconds later. If the subtitles come too late, use a negative number.
If the captions start in sync but drift further apart over time, the file was made for a different frame rate (for example 25 fps versus 23.976 fps). A constant shift won’t fix that; the drift grows by about 4% of the running time.
Why subtitles go out of sync
- A different cut. An intro or ad was added or removed after the subtitles were made — everything is off by the same amount. A shift fixes it.
- A different source. Subtitles made for another release of a film start at a different moment. A shift fixes it.
- A different frame rate. The gap grows through the video. That needs re-timing rather than a shift.
Subtitle sync FAQ
How do I fix out-of-sync subtitles?+
Drop the subtitle file on the time shift tool, enter how many seconds the subtitles are early or late, and download the shifted file. Use a positive number to delay subtitles and a negative number to bring them forward.
How precise is the subtitle time shift?+
The subtitle time shift is precise to the millisecond, so values such as 1.25 or -0.4 seconds can be entered.
Can only part of a subtitle file be shifted?+
The time shift tool moves the whole file. A single line can be re-timed in the subtitle editor, where every caption’s start and end can be changed.
What happens to captions shifted before the start of the video?+
Captions shifted before 00:00:00 are clamped to zero rather than removed, so no text is lost.
Does shifting subtitles change the file format?+
The shifted file keeps the format of the original: SRT stays SRT and VTT stays VTT.
Why do subtitles drift further out of sync over time?+
Subtitles drift when the file was made for a different frame rate, such as 25 fps instead of 23.976 fps. Drift grows through the video and needs re-timing, which a constant shift cannot correct.
Need subtitles from a video?
SubtitlePop listens to your video and writes the captions for you, with word-level timing. Try the subtitle generator or make a file with the SRT generator. New to subtitle formats? Read what an SRT file is.
SRT to VTT
Free SRT to VTT converter: convert SRT subtitles to WebVTT for HTML5 video and web players in one step. Runs in your browser — the file is never uploaded.
VTT to SRT
Free VTT to SRT converter: turn WebVTT captions into SRT for YouTube, Premiere Pro, DaVinci Resolve and desktop players. Private — runs in your browser.