DirectX X to OBJ Converter
FileFlip converts DirectX X to OBJ 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 an DirectX X file to OBJ?#
- Drop your DirectX X 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 OBJ 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 OBJ file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting DirectX X to OBJ lose quality?#
Not in the sense of pixels or samples. Converting DirectX X to OBJ rebuilds the file in OBJ's own model rather than re-encoding it, so everything OBJ 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 DirectX X files online?#
Yes, because nothing is uploaded. FileFlip converts DirectX X 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 DirectX X to OBJ actually does to the file#
Converting DirectX X to OBJ 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: DirectX X → OBJ |
| 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 | Dropped | The target format has nowhere to put it. |
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
- if the source carries a skeleton or animation, this target has no place to store it
What is an DirectX X file?#
An X file is Microsoft's DirectX mesh format, storing geometry, materials, textures, skinning and animation as a set of typed data templates, in either a human-readable text encoding or a tokenised binary one.
Use X only to keep compatibility with older DirectX SDK samples or a legacy pipeline built around the format.
Convert X to FBX or glTF for any current game or graphics pipeline, since DirectX itself has moved on from the format.
What is an OBJ file?#
An OBJ file is a plain-text 3D geometry format that Wavefront Technologies designed for its Advanced Visualizer software, storing vertex positions, texture coordinates and normals as human-readable lines of ASCII text.
Use OBJ when a static mesh needs to move between two different applications with the least risk of anything being misread.
Convert away from OBJ when the model needs animation, a skeleton, or to travel as a single file without a companion MTL.
DirectX X to OBJ questions people ask#
What is a DirectX X file used for?
An X file stores a 3D mesh for Microsoft's DirectX, including materials, textures, skinning and animation, laid out as a set of typed templates. It was the standard model format across the DirectX SDK samples through the 1990s and 2000s.
Is the X file format still used?
Rarely for new work. It's tied to Direct3D's Retained Mode API, which Microsoft stopped updating after DirectX 3.0 and later dropped outright, so current DirectX pipelines use FBX or glTF instead.
Why do some .x files look like source code instead of a 3D model?
The .x extension is shared with Lex lexical-analyzer source files on Unix systems, an unrelated format entirely. A text-encoded DirectX X file is also readable as plain text, but it starts with the header "xof" rather than Lex syntax.
What is an OBJ file used for?
An OBJ file stores the geometry of a single 3D model: its vertices, faces, texture coordinates and normals, written as plain text. It's used to move a static mesh between applications, since almost every 3D tool on every platform can read it.