Fix out-of-sync subtitles by shifting every SRT or VTT timestamp earlier or later with millisecond precision. Free, no signup required.
Everything runs in your browser — your file never leaves your device.
Positive values delay subtitles (show them later). Negative values show them earlier. Millisecond precision supported (e.g. -2.500).
The dialogue hasn't been spoken yet when the text appears. Shift by a positive offset (e.g. +2.5) to delay the subtitles until they match the audio.
The text lags behind the speech. Shift by a negative offset (e.g. -2.500) to bring the subtitles forward so they appear when the words are spoken.
An added intro or removed ad break shifts everything by a constant amount. Measure the difference at one line of dialogue and apply it as the offset.
Play the video and pause at a line of dialogue you can identify in the subtitle file. Compare the time the words are actually spoken with the timestamp in the file. The difference is your offset: if subtitles appear 2 seconds too early, shift by +2; if they appear 2 seconds too late, shift by -2. You can re-shift the output as many times as needed to fine-tune.
Yes. The tool automatically detects whether your input is SRT (timestamps like 00:01:30,500) or VTT (timestamps like 00:01:30.500) and keeps the same format in the output, so the shifted file works exactly where the original did.
Timestamps are clamped at 00:00:00,000. If you shift backward by more than the start time of the first cue, that cue will start at zero instead of going negative, which keeps the file valid for all players.
No. All parsing and shifting happens locally in your browser using JavaScript — your file never leaves your device. This makes the tool safe for confidential material like legal depositions, lecture captions, or unreleased video content.
The most common causes are a different video cut (intros, ads, or scenes added or removed), frame-rate differences between the version the subtitles were made for and your file, or an offset introduced during re-encoding. A constant offset is fixed by this tool; if the drift grows over time, the subtitles were likely made for a different frame rate.
PlainScribe transcribes audio and video into accurately timed SRT and VTT subtitles in 47 languages — $4 per audio hour, pay as you go, no subscription, and transcripts auto-delete after 7 days. Start with 30 free minutes.