Subtitle Shifter (SRT Resync)
Shift all the timings in an SRT subtitle file forward or back to fix sync.
Fixing subtitles that are out of sync
When subtitles run ahead of or behind the audio by a consistent amount, the whole file needs its timings shifted. This moves every timestamp in an SRT file forward or back by the offset you set, so subtitles that are uniformly out of sync line back up with the speech.
Load your SRT and enter the time offset to shift it.
Constant offset versus drift
Shifting works perfectly for a constant offset — where the subtitles are simply early or late by the same amount throughout, often because they were made for a version of the video with a different intro length. Distinguish that from drift, where subtitles start in sync but gradually slide out over the runtime; that comes from a frame-rate mismatch and needs stretching, not a simple shift. For the common constant-offset problem, nudging the whole file by the right amount fixes it cleanly. Finding the offset is a matter of spotting how far off one clear line is and applying that to all.
Questions & answers
What problem does shifting fix?
Subtitles that are consistently early or late by the same amount throughout, moving every timestamp by the offset you set.
What if subtitles drift out of sync over time?
That is a frame-rate mismatch, not a constant offset, and needs stretching rather than a simple shift.
Is my file uploaded?
No. The shifting happens in your browser.