Free, instant, and entirely in your browser — your subtitle file is never uploaded.
MicroDVD counts frames, not seconds — this has to match the video.
Plain text is the subtitle with the subtitle part removed: the spoken lines, in order, with no timing at all.
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.
A script becoming a subtitle project. This is the emptiest starting point of the three: no timing to inherit and no styling to inherit, so what you get is every line in a proper [Events] section under one Default style, evenly spaced from zero. Nobody should ship this file — it is a skeleton to open in Aegisub, where you will time it against the audio and then do the actual design. It exists so the first hour of the job is not retyping.
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.
Plain text has no timing, so this conversion has to invent it. Each line becomes a cue of a fixed length, laid end to end from the start of the file. The words will be right and the timing will not — it is a scaffold, not a finished subtitle. The honest workflow is to convert here, then open the result in a sync tool and line it up against the video.
No. The conversion runs in your browser using JavaScript — your TXT 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.
A script becoming a subtitle project. This is the emptiest starting point of the three: no timing to inherit and no styling to inherit, so what you get is every line in a proper [Events] section under one Default style, evenly spaced from zero. Nobody should ship this file — it is a skeleton to open in Aegisub, where you will time it against the audio and then do the actual design. It exists so the first hour of the job is not retyping.
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 TXT, it says so and points you at the all-format converter instead of producing a broken file.