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ExplainerWhat is an OBJ file?
An OBJ file is a simple, widely supported format for storing a 3D model's geometry — its vertices and faces. Created by Wavefront, it's one of the oldest and most universal 3D formats, which is why almost every 3D tool can read and write it. A companion .mtl file describes the model's materials.
What's inside
- The .obj — the shape: points in space and the faces that connect them.
- The .mtl — the surface: colors and references to texture images.
Keep the two together (and any textures) when you share an OBJ so its materials come along.
Why OBJ is everywhere
It's plain, well-documented, and ancient in software terms, so support is universal. When you just need to move geometry from one 3D app to another without fuss, OBJ almost always works.
How it compares
| Format | Best for | Notes |
|---|---|---|
| OBJ | Universal geometry exchange | Simple; limited materials, no animation |
| glTF / GLB | Web, AR, real time | Rich materials + animation |
| FBX | Animation pipelines | Feature-rich but proprietary |
| .blend | Editing in Blender | Native Blender scene |
Turn a floor plan into an OBJ
Upload a 2D plan and export a universal OBJ model — plus glTF, .blend, and CAD files.
Get early access →Frequently asked questions
What is an OBJ file used for?
An OBJ file stores a 3D model's geometry — its vertices and faces — in a simple, widely supported format used to move models between 3D applications like Blender, Cinema 4D, and 3ds Max.
What is the .mtl file that comes with an OBJ?
The .mtl (material template library) file accompanies an OBJ and describes its materials — colors and texture references. The OBJ holds the shape; the MTL holds the surface look.
OBJ vs glTF vs FBX — what's the difference?
OBJ is simple and universal but carries limited material and no animation data. glTF is modern and web-friendly with richer materials and animation. FBX is common in animation pipelines but proprietary. Pick OBJ for plain geometry exchange.
Can I open an OBJ file for free?
Yes. Free tools like Blender open OBJ files, and most 3D viewers support them, which is a big reason OBJ remains popular.