GLB vs FBX vs OBJ: which 3D format should you use?
If you download 3D models, you will meet the same three formats again and again: GLB (glTF), FBX and OBJ. They can all hold a mesh, but they differ a lot in what else they keep — materials, animations, scale — and in which tools read them. Here is a practical comparison so you can pick the right one, plus a quick look at STL and USDZ.
The short answer
- GLB / glTF — best default for the web, AR/VR, Godot, Blender and modern engines. One file, PBR materials, animations included.
- FBX — best when a tool specifically expects it: Unity Humanoid rigs, Unreal’s classic pipeline, Mixamo, many DCC apps.
- OBJ — best for simple static meshes and maximum compatibility with old software. No animation.
Comparison table
| GLB / glTF 2.0 | FBX | OBJ | |
|---|---|---|---|
| Owner | Khronos Group, open standard | Autodesk, proprietary | Open, from Wavefront (1990s) |
| Files | 1 file (.glb) or .gltf + .bin + images | 1 file, textures embedded or external | .obj + .mtl + images |
| Materials | PBR metallic-roughness, standardized | Varies by exporter | Basic (MTL), no real PBR |
| Skeleton & animation | Yes (skins, clips, morph targets) | Yes | No |
| Web / three.js | Native, fastest | Possible, heavier | Possible, no animation |
| Typical size | Small; supports Draco/meshopt compression | Medium to large | Large (text format) |
GLB and glTF
glTF 2.0 was designed as a delivery format: the data is laid out so engines and browsers can load it with minimal processing. GLB is the binary container that packs everything into one file — which is why every model on Brojek GLB downloads as GLB. Materials follow one well-defined PBR model, so a model looks the same in Blender, three.js and Godot. It also supports extensions like Draco and meshopt compression, KTX2 textures and lights. Unity needs a free package (glTFast); Unreal Engine 5 imports it through Interchange; Roblox Studio’s 3D Importer accepts it in recent versions. See free GLB files and glTF models.
FBX
FBX has been the industry interchange format for decades, especially for rigged and animated characters. Unity’s Humanoid retargeting, Mixamo and many animation pipelines are built around it. The downside is that it is proprietary and loosely specified: two exporters can write “FBX” that imports differently, materials often need fixing, and scale/axis issues are common. Use FBX when a specific tool asks for it — you can always create one from a GLB in Blender (how to open GLB in Blender).
OBJ
OBJ is a simple text format that nearly every 3D program since the 1990s can read. It stores geometry, UVs and normals, and refers to a separate .mtl file for basic materials. It has no skeleton, no animation and no modern PBR materials, and files get large because they are plain text. It is still handy for static props, quick exchanges, sculpting tools and some printing workflows. The Character Creator exports OBJ for exactly that reason.
What about STL and USDZ?
- STL is for 3D printing: just triangles, no color or materials. Slicers love it. The Character Creator exports STL scaled to about 10 cm — see 3D printing models.
- USDZ is Apple’s packaged USD format for AR Quick Look on iPhone and iPad. The Character Creator exports it too.
Which should you pick?
- Making a web game or WebXR experience → GLB (three.js guide).
- Using Godot → GLB (Godot guide).
- Using Unity → GLB with glTFast, or FBX for Humanoid rigs (Unity guide).
- Using Roblox Studio → GLB in recent versions, otherwise FBX/OBJ (Roblox guide).
- 3D printing → STL. iPhone AR → USDZ.
Converting between formats
Blender is the free universal converter: import any of these formats, then export to another. Keep in mind conversions only keep what both formats support — exporting an animated GLB to OBJ drops the animation, and exporting to STL drops colors. For command-line work with glTF specifically, the open-source gltf-transform tool can compress, resize textures and convert between .glb and .gltf.
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