PMX to glTF Converter
FileFlip converts PMX to glTF 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 glTF?#
- 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 glTF 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 glTF file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting PMX to glTF lose quality?#
Not in the sense of pixels or samples. Converting PMX to glTF rebuilds the file in glTF's own model rather than re-encoding it, so everything glTF 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 glTF actually does to the file#
Converting PMX to glTF 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.
| Engine | Assimp |
|---|---|
| Conversion path | One step: PMX → glTF |
| 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, or a ZIP when the source carries separate materials or buffers |
| 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 | Sometimes | Survives for some files and not others. |
Worth knowing before you start:
- the result is a single file when the model has no external materials or buffers, and a ZIP when it does
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 glTF file?#
A glTF file is a JSON scene description, developed by the Khronos Group and first released in 2015, that lists a model's meshes, PBR materials, animations and scene hierarchy while its binary geometry and textures sit alongside it in separate buffer and image files.
Use glTF's JSON form when a pipeline needs to inspect or hand-edit the scene structure directly, since it's plain, indexed JSON.
Convert glTF to GLB when the model needs to travel or load as a single file instead of a folder of JSON, buffers and textures.
PMX to glTF 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's the difference between glTF and GLB?
glTF is a JSON text file that references its geometry buffers and textures as separate files, while GLB packs that same JSON, the buffers and the textures into a single binary file. Both describe the identical data model; GLB just bundles everything one file needs to travel as one upload.