Free, instant, and entirely in your browser — your subtitle file is never uploaded.
MicroDVD counts frames, not seconds — this has to match the video.
MicroDVD is the odd one out: it counts frames, not time. Each line is {start}{end} followed by the text, with a pipe between display lines. There is no timestamp anywhere in the file.
ASS is a typesetting language that happens to carry subtitles. Named styles, exact positioning, rotation, fades, karaoke timing and vector drawing all live in the file, split across a [Script Info], a styles and an [Events] section.
This is a restoration. Someone has an old release whose subtitles survive only as frame counts, and wants to rebuild it properly — which means getting the lines into a format that can hold real timing and real typesetting before any of that work can start. Do the frame rate carefully: everything you build afterwards sits on top of the times produced here, and correcting a rate later means redoing the timing rather than adjusting it.
You want ASS because you are about to typeset, not merely translate. Going into ASS is what opens the door to named styles, exact positioning, fades and karaoke timing in an editor like Aegisub. The conversion does not create any of that — it gives you a clean file with one default style, ready for the work to begin.
The target format can do far more than the source ever could, but a conversion cannot invent design that was never there. What you get is a well-formed file with a single default style — correct, playable, and ready to be styled properly in an editor like Aegisub. The gain is real but it is potential: the capability is now available to you, not already used. Because MicroDVD is the source here, the frame rate is something the file does not reliably tell you. The numbers inside it are frame counts, and turning them back into seconds requires the rate the file was authored for. Many of these files declare it on a leading {1}{1} line, and when yours does that value is used automatically. When it does not, the figure above is an assumption — if the result drifts steadily rather than sitting at a constant offset, that assumption is what to change.
No. The conversion runs in your browser using JavaScript — your SUB file is read from disk, converted in memory and handed back as a download. Nothing is transmitted, so there is nothing for us to store or delete. You can disconnect from the internet after this page loads and the conversion still works.
This is a restoration. Someone has an old release whose subtitles survive only as frame counts, and wants to rebuild it properly — which means getting the lines into a format that can hold real timing and real typesetting before any of that work can start. Do the frame rate carefully: everything you build afterwards sits on top of the times produced here, and correcting a rate later means redoing the timing rather than adjusting it.
The page checks before it converts. Subtitle formats are identified by what is inside the file rather than by the extension — which matters, because .sub alone is used by three unrelated formats. If you hand this page something that is not SUB, it says so and points you at the all-format converter instead of producing a broken file.