Multi-step browser workflow
Convert & Shift Subtitles
Detect a subtitle format, shift every timestamp by a positive or negative offset and export the corrected captions as WebVTT.
Convert subtitles and shift timestamps together
This workflow detects supported subtitle input, applies the same timing offset to every cue and exports WebVTT. It avoids converting a file first and then reopening the converted output in a separate timing tool.
How to shift subtitle timing
- Paste or add supported subtitle content.
- Enter an offset in milliseconds.
- Use a positive number to delay cues or a negative number to move them earlier.
- Run format detection, conversion and timestamp adjustment.
- Preview the WebVTT output and download it.
When a fixed offset works
Use a fixed shift when every caption is early or late by approximately the same amount—for example, when subtitles start two seconds before the matching speech. A fixed offset cannot repair timing that gradually drifts during the video.
Format conversion limitations
SRT, VTT, ASS, SSA, SBV and plain text use different timing and styling features. WebVTT output retains supported cue timing and text, but complex ASS or SSA positioning, fonts and effects may be removed.
Preview before publishing
Processing is local, but the result still needs visual review against the video. Check the first cue, a cue near the middle and the final cue before replacing the original subtitle file.
Frequently asked questions
Convert & Shift SubtitlesFAQ
Which subtitle formats are detected?
SRT, VTT, ASS, SSA, SBV and plain text are supported.
Can I move subtitles earlier?
Yes. Use a negative millisecond offset to move cues earlier, or a positive offset to move them later.
Which output format is created?
The workflow exports WebVTT for use with HTML5 video players and other systems that accept VTT captions.
Is subtitle styling preserved?
Not always. Converting styled ASS or SSA input to WebVTT can remove unsupported positioning and style information.
Are subtitle files uploaded?
No. Detection, timing adjustment and conversion run locally in the browser.