GLB (GL Transmission Format — Binary)
GLB is the binary, single-file variant of glTF 2.0, the 'JPEG of 3D.' It packages 3D geometry, materials, textures, and animations into one compact file. GLB is the standard for real-time 3D on the web, AR/VR, and game engines.
MIME Type
model/gltf-binary
Type
Binary
Compression
Lossless
Advantages
- + Single file — all data (meshes, textures, animations) in one GLB
- + GPU-ready binary data for fast rendering
- + Industry standard for WebGL, AR, and 3D commerce
- + PBR (Physically Based Rendering) materials built-in
Disadvantages
- − Not human-readable — use glTF (JSON + .bin) for debugging
- − Limited support for advanced animation (no morph target names in some tools)
- − Newer format — some legacy 3D tools may not support it
When to Use .GLB
Use GLB for web 3D, AR/VR content, and any real-time rendering scenario where a single-file format is preferred.
Technical Details
GLB files contain a 12-byte header, a JSON chunk (scene graph, materials, animations), and a binary chunk (geometry, textures). The binary data is directly GPU-uploadable with minimal parsing overhead.
History
The Khronos Group released glTF 2.0 (and GLB) in 2017 as a royalty-free transmission format for 3D content. It was designed for efficient delivery and GPU-ready rendering, gaining rapid adoption in WebGL, three.js, and AR platforms.