Shift subtitle timestamps forward or backward with millisecond accuracy for SRT and WebVTT files.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. Zero egress.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
Paste your SRT or WebVTT subtitle content into the editor.
Adjust time shift in milliseconds (+1000ms for +1s delay, -500ms for earlier).
Download the updated .srt or .vtt file ready for media playback.
The synchronizer automatically clamps minimum timestamps to 00:00:00,000 to prevent media player parsing errors.
Yes, the parser automatically detects comma (00:00:01,500) and period (00:00:01.500) millisecond separators.
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