Rescale Subtitle Timeline
Stretch or shrink an existing subtitle timeline using a chosen factor.
Work locally
Local text only, up to 1 MiB and 5000 cues. Unsupported VTT styling blocks are refused, not silently lost.
Use the controls above to begin. Files stay on this device.
Results
How to use rescale subtitle timeline
Select a local file if requested, or enter values and review them. Choose Process in browser, review the output and download it before leaving the page. If the browser cannot decode a file, the tool reports the limitation rather than uploading it elsewhere.
Method and accuracy
Use 0.5–2.0 to adjust timestamps for a uniformly changed video timeline. This does not edit video playback speed. Processing occurs within device and browser limits; actual player compatibility can differ by format. No generated captions, speech transcription or AI enhancements are offered.
Related tools
Manual caption editor · Basic media inspector · Bitrate calculator
How this tool works
Stretch or shrink an existing subtitle timeline using a chosen factor.
What to check before sharing
The editor works on basic local subtitle text. It cannot transcribe speech or decode image-based subtitle tracks. Unsupported styling must be rejected rather than silently lost.
No AI or paid processing API. The site does not intentionally upload selected media. See privacy, current format limitations and browser processing explained.