GLB vs FBX — Which 3D Format Should You Use?

GLB and FBX are both full-featured 3D formats that support geometry, materials, textures, animation, and rigging. But they come from completely different worlds — GLB from the open web standards community, FBX from Autodesk's proprietary ecosystem. Choosing the wrong one for your pipeline creates friction that costs time every single day. This guide gives you the definitive breakdown.

Format Overview

GLB (GL Binary) is the binary container format of the glTF 2.0 specification, developed by the Khronos Group — the same open standards body behind OpenGL and Vulkan. It was designed specifically for real-time rendering on the web and in game engines. First stable release: 2017.

FBX (Filmbox) was created by Kaydara in 1996, acquired by Autodesk in 2006. It is the dominant interchange format for the VFX and game development industry — every major DCC tool (Maya, 3ds Max, Blender, Cinema 4D, ZBrush) has deep FBX support. Despite being proprietary, its ubiquity has made it the de-facto standard for moving rigged characters between applications.

Ownership and Licensing

What Each Format Can Store

Software Support

File Size and Compression

For equivalent content, GLB typically produces smaller files than FBX due to two key features:

• Draco mesh compression — reduces geometry data by 70–90%, a GLB-specific extension not available in FBX
• KTX2/Basis Universal textures — compressed GPU textures embedded in the GLB file, both reducing size and eliminating the GPU decompression step at runtime

A character model that is 8MB as FBX might be 1.2MB as a Draco-compressed GLB with KTX2 textures — a 6.5× size reduction with identical visual quality at runtime.

Game Engine Compatibility

Unity: FBX has been Unity's native import format for over a decade. GLB support via GLTFast (Unity's official package) is excellent for runtime loading but requires a build step for the import pipeline. For shipped characters, FBX at import time + GLB at runtime is a common pattern.

Unreal Engine: FBX is the primary import format. GLB support requires a third-party plugin. For most Unreal workflows, FBX remains the correct choice.

Godot: GLB is Godot's preferred import format. FBX support was added in Godot 4 but is less mature. For Godot projects, GLB is clearly the right choice.

Web-based engines (Three.js, Babylon.js, PlayCanvas): GLB only. FBX is not supported in any web-based 3D runtime.

Web and AR

This is where the choice is unambiguous: GLB always wins for web and AR.

• Three.js, Babylon.js, and every other JavaScript 3D library has a GLTFLoader. None have an FBXLoader suitable for production use.
• Google's <model-viewer> web component only accepts GLB
• Android AR (SceneViewer) only accepts GLB
• WebXR scenes use GLB
• Facebook 3D posts accept GLB

If your destination is any web or AR experience, convert to GLB before deployment.

DCC Workflow

For content creation pipelines (modeling → rigging → animation → rendering), FBX has historically been the lingua franca. The reason is Maya — the dominant tool for character animation — and its first-class FBX support. When moving assets between Maya, ZBrush, Blender, and game engines, FBX is the most reliable interchange format.

However, this is changing. Blender's GLB export is now excellent, and game engines are improving their GLB pipelines. For pipelines that do not involve Maya or 3ds Max, GLB is increasingly viable as the primary interchange format.

When to Use Each

Frequently Asked Questions