Subtitle converter & time shift
Convert SRT, WebVTT and ASS captions locally, and shift the entire timeline by a precise number of seconds.
How to use this tool
- Choose UTF-8 SRT, VTT or ASS files.
- Select an output format and optional positive or negative time shift.
- Convert, review the plain-text preview, and download each result or a ZIP.
Keep the original files and inspect the exported result before publishing or sharing it. Processing happens on this device; engine and library assets download when needed.
Frequently asked questions
What happens to ASS styling?
Font styling, positioning, karaoke, effects and VTT cue settings are removed. ASS vector drawings are rejected. Output ASS uses a basic default style; verify it in your subtitle editor.
Can I move subtitles earlier?
Enter a negative shift in seconds. A conversion is rejected if any cue would start before zero; cues are never silently clipped.
Are all subtitle features supported?
This converter preserves plain caption text and valid timings, not every subtitle extension. It accepts UTF-8 and rejects malformed or reversed timestamps. ASS timing rounds to centiseconds.
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