ffsubsync — sync subtitles in your browser

Sync a subtitle file against a reference subtitle — entirely on your machine. Nothing is uploaded.

Reference type

Subtitle file Video / audio file

Reference subtitles — a correctly-timed .srt / .ass / .ssa Subtitles to sync — the out-of-sync file to fix

Advanced — optional; leave unchecked for the standard sync

Don't fix framerate ? Golden-section search ? Fix mid-file breaks ?