Subtitle Time Shifter
Move SRT, VTT or ASS subtitles forward or backward in milliseconds. Preserve ASS styling and VTT cue settings when shifting.
How to use
A positive offset delays subtitles; a negative offset shows them earlier. Enter an integer number of milliseconds, up to 24 hours in either direction. Both cue start and end times move by the same amount.
By default a negative result is an error. With clipping enabled, a cue crossing zero begins at zero and a cue ending at or before zero is removed. Partial clipping changes that cue’s duration. If all cues disappear, no result is produced.
Behavior and limits
ASS shifting changes only Dialogue start/end fields and retains the original styles and other events. ASS still rounds to centiseconds. WebVTT cue identifiers, settings, NOTE, STYLE and REGION blocks are retained. This does not stretch timing to fix frame-rate drift.
Questions & answers
Should I enter seconds or milliseconds?
Milliseconds: 1500 means 1.5 seconds later; -1500 means 1.5 seconds earlier.
Can I use this without uploading data?
Processing runs on your device. Input is not sent to a conversion API. Keep the page open until the result is ready.