How it works
Complete the job in three clear steps
- Choose or paste an SRT or VTT caption track.
- Review the timing and create a retimed subtitle file.
- Preview or download the result before closing the page.
Private Lucaden subtitle tool
Subtitle Time Shifter
Move every SRT or VTT cue earlier or later by an exact millisecond offset.
Free to use Your subtitle text and files stay in this browser and are not uploaded to Lucaden.
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Important
Check the result before relying on it
Keep an untouched copy of important source files. Browser processing depends on available device memory, and you should inspect every downloaded result before deleting the original.
Practical details
What this Lucaden tool does
Move every SRT or VTT cue earlier or later by an exact millisecond offset.
The parser normalizes SubRip and WebVTT cues into millisecond timestamps. Lucaden then serializes a new file instead of modifying the original.
Included capabilities
- Earlier and later shifts
- Millisecond precision
- SRT or VTT output
- Negative-time clamping
Useful for
- Fix delayed captions
- Correct early subtitles
- Align a track after trimming
- Synchronize translated captions
Questions
About this tool
What happens to a cue shifted before zero?
Lucaden clamps its start to 00:00:00.000 and preserves a positive duration.
Can this fix timing drift?
A constant shift fixes one uniform offset. Gradual drift needs cue-by-cue editing or time scaling.
Open-source foundations
Built transparently
Lucaden documents its standards sources, architectural references, and permissive runtime dependencies while keeping this workspace consistent with the Lucaden interface.