Practical guides
How to fix subtitles that are out of sync
A fixed timing shift works when every subtitle is early or late by roughly the same amount. Before editing, compare a clear spoken phrase with its caption near the beginning and near the end. If the delay keeps changing, one offset will not repair the whole file.
Should the subtitle offset be positive or negative?
Use a positive offset to show captions later. Use a negative offset to show them earlier. Calculate the adjustment as the intended caption start minus its current start. For example, speech starting at 14 seconds with a caption starting at 12.5 seconds needs +1.5 seconds.
| Problem | Adjustment | Example |
|---|---|---|
| Subtitles appear too early | Positive: move later | +1.500 seconds |
| Subtitles appear too late | Negative: move earlier | −1.500 seconds |
| Delay grows during playback | A fixed shift is insufficient | Check the video version or retime sections |
How to shift an SRT or VTT file
SubtitleDock moves every cue by the same amount and keeps the original subtitle format. It preserves text, cue durations and styling; it does not modify the recording.
- Open Subtitle Time Shifter and choose or paste your UTF-8 SRT or VTT subtitles.
- Enter the offset in seconds, with up to three decimal places. Preview a known cue to confirm the direction.
- Download the shifted file and play it with the matching recording. Check the beginning, middle and end before replacing any working copy.
What if a shift creates a negative timestamp?
If the first caption starts at one second, moving every cue two seconds earlier would put that caption before zero. The tool stops the operation instead of silently cutting off or deleting it. Use a smaller offset or edit the affected cues separately in a subtitle editor.
WebVTT inline timestamps move with their cues. Stream-mapped VTT files are not supported by this time shifter. Read any error before downloading; a new extension cannot resolve a timing error.
When a time shift will not fix subtitle sync
If the opening is correct but captions become late several minutes later, check whether the subtitle file and video come from different edits. An inserted introduction, removed scene or speed change can require different adjustments in different sections.
For a known playback-rate change that changes video duration, use the Subtitle Frame Rate Converter. A 24 fps version played at 25 fps needs times multiplied by 24/25, or 0.96. Simply re-encoding to a new frame rate without changing duration needs no caption scaling.
Use the matching subtitle version, a subtitle editor with section retiming, or create a fresh transcript from the final recording. For newly generated captions, review individual start and end times in Video to Text before export. Keep the original file so you can compare your changes.