Shift every timestamp in a subtitle file by a fixed amount locally in your browser - handy when audio and text have drifted apart. No upload.
Running locally on your device ...
Running locally on your device ...
0%
Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Anyone who has attached a downloaded subtitle file to their own video rip knows the problem: the text runs a few hundred milliseconds or even several seconds ahead of or behind the spoken word - usually because the subtitles were made for a different cut (with an intro, a different frame rate, or trimmed ad breaks). This tool shifts every single timestamp in the file by the same, freely chosen amount, without touching the text itself.
Technically, the tool automatically detects whether it is looking at an SRT, WebVTT, ASS/SSA, SBV, TTML, SAMI or LRC file, adds the entered number of seconds (positive = later, negative = earlier) to the start and end time of every subtitle, and writes the result back out in the SAME format - an SRT file stays an SRT file, a VTT file stays a VTT file.
A subtitle that would shift entirely before the zero point of the recording is honestly removed from the output instead of being left as a broken negative time; a subtitle only partly before it starts at zero instead. The whole calculation happens locally in your browser.
| Input formats | SRT, VTT, ASS, SSA, SBV, TTML, DFXP, SMI, SAMI, LRC |
|---|---|
| Auto-conversion | MP4 |
| Output format | SRT |
| Batch processing | No |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: All timestamps are shifted by the same fixed amount - a drift that changes over the running time (e.g. from a different frame rate) needs more than a plain shift. A subtitle that shifts entirely before the new zero point is removed; one that only straddles it starts at zero seconds. Text and order stay unchanged.
No, the entire shift runs locally in your browser; the file never leaves your device.
SRT, WebVTT, ASS/SSA, SBV, TTML/DFXP, SAMI and LRC - the format is detected automatically and kept on output.
They are honestly removed from the result instead of being output as a broken negative time; a subtitle only partly affected starts at zero.
Yes, the range covers -3600 to 3600 seconds (one hour in either direction).