PMX to 3MF Converter
FileFlip converts PMX to 3MF entirely inside your browser, using Assimp compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a PMX file to 3MF?#
- Drop your PMX file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to 3MF and the conversion starts on its own. FileFlip downloads 11.2 MB of WebAssembly the first time and nothing after that, then runs Assimp on your own machine.
- Save the 3MF file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting PMX to 3MF lose quality?#
Not in the sense of pixels or samples. Converting PMX to 3MF rebuilds the file in 3MF's own model rather than re-encoding it, so everything 3MF can represent comes through exactly and anything it cannot has to be dropped. Expect the geometry to be exact, and anything the target has no place for, such as a rig, to be left behind.
Is it safe to convert PMX files online?#
Yes, because nothing is uploaded. FileFlip converts PMX 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 PMX to 3MF actually does to the file#
Converting PMX to 3MF runs on Assimp, downloads 11.2 MB of WebAssembly the first time and nothing after that, rebuilds the file in the target's own model, and drops skeleton and animation.
| Engine | Assimp |
|---|---|
| Conversion path | One step: PMX → 3MF |
| Downloaded to your browser | 11.2 MB, once, then cached by your browser |
| Quality | Rebuilt in the target's model |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Materials | Sometimes | Survives for some files and not others. |
| Textures | Sometimes | Survives for some files and not others. |
| Skeleton and animation | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- if the source carries a skeleton or animation, this target has no place to store it
What is a PMX file?#
A PMX file is a binary character model for MikuMikuDance, the successor to the older PMD format, built by Yu Higuchi's tools to hold a mesh alongside its bones, facial morphs and rigid-body physics as one package that MMD loads and animates directly.
Use PMX when a character needs to be posed, animated or physics-simulated inside MikuMikuDance or the wider MMD tool ecosystem.
Convert PMX to glTF or FBX when an MMD character needs to move into a game engine or renderer outside the MMD ecosystem.
What is a 3MF file?#
A 3MF file is a ZIP archive of XML documents, published by the 3MF Consortium in 2015 as 3D printing's replacement for STL, adding the colour, material, unit and multi-object placement data STL never had.
Use 3MF over STL whenever colour, material or multiple positioned objects need to travel with the geometry to the printer.
Convert 3MF to STL only when the destination software is old enough to not support 3MF at all.
PMX to 3MF questions people ask#
What is a PMX file?
A PMX file is a MikuMikuDance character model, storing a mesh together with its bones, facial morphs and rigid-body physics in one binary file. It's the successor to the older PMD format and the format almost all current MMD character content is distributed in.
What's the difference between PMD and PMX?
PMD is the older MikuMikuDance model format, and PMX succeeded it with a more flexible bone and morph system, support for more materials, and additional physics options. PMX Editor can open and convert PMD files, and current MMD content is essentially all PMX now.
Can I open a PMX file outside MikuMikuDance?
Yes, Blender opens PMX files through the community mmd_tools add-on, which reads the mesh, bones, morphs and physics much the way MikuMikuDance does. Outside of MMD-focused tools, native PMX support is rare.
What is a 3MF file?
A 3MF file is a 3D printing format, a ZIP archive of XML, published by the 3MF Consortium in 2015 to replace STL. It adds colour, material, real-world units and multiple objects with their placement on the build plate, none of which STL can store.