glTF 2.0 (JSON) .gltf
The open standard for the web. PBR materials, readable JSON.
What a .gltf file holds
glTF 2.0 is the Khronos Group’s royalty-free runtime format, often described as "the JPEG of 3D". The .gltf flavour is human-readable JSON that describes the scene graph, and points at binary buffers and image files sitting next to it. It defines a single physically based material model, so a glTF file looks the same in every conforming renderer, which is rare in 3D. Use .gltf when you want to inspect or hand-edit the file, and .glb when you want to ship it.
Commonly seen in: three.js, Babylon.js, Godot, Blender, Adobe Substance 3D.
| Data | Stored in glTF |
|---|---|
| Geometry | Yes |
| Materials and colour | Yes |
| Texture maps | Yes |
| Animation and rigs | Yes |
| Scene hierarchy | Yes |
| Read here | Yes |
| Written here | Yes |
Tested against a real file
The last sweep loaded BoxTextured.gltf from Assimp test models, glTF 2.0 with its 2 sidecar files through the viewer on this site: 12 triangles across 1 meshes and 1 materials, in 2.0 seconds. Every format's result is on the test results page, run 2026-09-08.
Files to bring with it
Drop the .bin buffer and texture images in together with the .gltf.
Convert glTF to another format
Every pairing has a page saying what survives the trip.
Convert something else to glTF
Other things to do with a .gltf file
Questions about glTF
How do I open a .gltf file?
Drop it into the viewer on this site and it opens in the browser, with the scene tree, the materials and the mesh statistics. Nothing is uploaded. If you want it in another program instead, convert it to GLB, which almost everything reads.
Is glTF a good format to archive in?
glTF carries geometry, materials, textures and animation, so an archive copy keeps nearly everything. The usual caveat applies: a format is only as future-proof as the readers that exist for it, and .gltf is well served.
Does converting glTF lose quality?
Geometry is copied vertex for vertex, so the shape does not degrade. What gets lost is whatever the target format has no field for: convert to STL and the materials go, convert to OBJ and the animation goes. The comparison table on each converter page says exactly which.
Written up on the blog
Formats that hold the same things
Or go back to the full format reference.