MPSub Converter
FileFlip converts MPSub files into 6 other formats entirely inside your browser, using FFmpeg compiled to WebAssembly. The MPSub file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. There is no file-size limit and no account to create.
How do I convert an MPSub file?#
- Drop your MPSub file onto the converter at the top of this page, or click it to pick one from your computer.
- Choose the format you want out of it. FileFlip downloads the engine that conversion needs, once, and your browser caches it.
- Conversion starts the moment you pick the format, and the result is yours to download. The work happens in this tab, so nothing is uploaded and nothing is queued.
Is it safe to convert MPSub files online?#
Yes, because nothing is uploaded. FileFlip converts MPSub files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What happens to a MPSub file#
FileFlip converts MPSub into 6 formats with FFmpeg, all of it inside the browser tab. Each conversion below names the engine it uses, what it downloads, and exactly what that conversion keeps or drops.
| Category | Subtitles |
|---|---|
| File extension | .mpsub |
| FileFlip support | Read only, so it is a source rather than a target |
| Conversions available | 6 |
| Engines | FFmpeg |
| Downloaded to your browser | 30.8 MB on the first conversion, then cached |
What is an MPSub file?#
An MPSub file is MPlayer's native subtitle script, opening with a FORMAT line that declares whether the lines that follow are timed in seconds or in frames, with each subtitle giving its gap since the previous line and its own duration rather than an absolute start and end time.
Recognize MPSub if it turns up as MPlayer's own subtitle export; there's little reason to author new subtitles in it outside that ecosystem.
Convert MPSub to SRT to get absolute, frame-rate-independent timecodes that any player can read.
The MPSub file format reference covers the specification, the programs that open one, and what each conversion keeps or drops.
MPSub questions people ask#
What is an MPSub file?
An MPSub file is MPlayer's own subtitle format, where each line is timed by its offset from the previous line's end and its own duration, rather than by an absolute start and end timecode. A FORMAT line at the top of the file declares whether those offsets are measured in seconds or in frames.
Does MPSub timing break if the video's frame rate changes?
It depends on how the file was authored. An MPSub file with FORMAT=TIME is timed in seconds and stays in sync at any frame rate, but one authored in frame mode times its offsets in frame counts and drifts out of sync the same way MicroDVD does when the frame rate changes.
Can I convert an MPSub file to another format?
An MPSub file can be read and converted into a format like SRT that uses absolute, frame-rate-independent timecodes. Producing MPSub as an output is uncommon, since it's a format MPlayer exports rather than one other tools generate.