Convert MicroDVD SUB to SRT
Convert MicroDVD .sub subtitles to SRT in your browser. Set the framerate the file was written for, or let the file declare it. Nothing is uploaded.
MicroDVD .sub files do not store times at all — they store frame numbers, which only become times once you know the framerate of the video they were made for. That is why a .sub that plays perfectly on one rip drifts steadily on another. Subtitle Doctor reads the frame numbers, converts them at the rate you pick (or at the rate the file declares on its own first line), and writes real SRT timestamps that no longer depend on the video running at any particular speed.
Worth knowing
- Two completely different formats share the .sub extension: MicroDVD is plain text that starts with {0}{25}, while VobSub is a binary image track that always arrives beside a matching .idx file. This page reads the text one — VobSub needs OCR instead.
- Because MicroDVD counts frames, the same file lands in different places on a 23.976fps and a 25fps video. The gap is 4.27%, which is over two and a half minutes by the end of an hour.
- Many files declare their own rate on the first line as {1}{1}23.976. When yours does, that number wins and the framerate picker is ignored — the file knows better than a default.
- A pipe character is MicroDVD's line break: "First line|Second line" becomes two real lines in the SRT.
- Control codes are handled by meaning, not by deletion: {y:i} becomes an <i> tag, while colour and font codes like {c:$0000ff} have no SRT equivalent and are dropped.
FAQ
How do I know which framerate my .sub file needs?
Check the video it came with — a media player's file info panel shows it. Film-sourced releases are almost always 23.976, European broadcast material 25. If the subtitles start right but drift, the rate was wrong; if they are wrong from the first line, you need a shift instead.
My .sub file came with a .idx file and will not load. Why?
That pair is VobSub: the .sub holds bitmap images of the subtitles rather than text, so there is nothing to convert without running OCR over the pictures. Extracting text from image subtitles is what the Blu-ray SUP tool does today; VobSub support is on the list.
The subtitles drift further out of sync as the film goes on. What went wrong?
Drift that grows over time is always a rate mismatch, never an offset. Convert again with the other common framerate, or fix the finished SRT with two-point sync, which stretches the whole file to fit two moments you mark yourself.