Delay or Speed Up Subtitles Online
Convert subtitles between SRT and VTT, shift their timing by milliseconds or seconds, and renumber cues — privately in your browser.
Processed entirely in your browser — nothing you enter here is ever uploaded.
Result
About this tool
This page opens the subtitle converter with timestamp shifting already selected — load your .srt or .vtt file, enter the offset and download the corrected copy.
If the subtitles appear too early, they are running ahead of the audio: enter a positive offset to delay them. If they appear too late, they lag behind: enter a negative offset to speed them up. Shifts as fine as a few hundred milliseconds are usually enough to fix the sync.
Every timestamp in the file is moved by the same amount, cues that would go below zero are clamped at 00:00, and the whole operation happens locally in your browser — the file is never uploaded anywhere.
Example. An SRT cue numbered 1 from 00:00:01,000 to 00:00:03,000 becomes a VTT cue, and a +500 ms shift moves both timestamps later by half a second.
Limit. Conversion is between SRT and VTT only, with shift and renumber, and not to ASS or SUB.