glTF is the Khronos royalty-free standard for transmitting 3D scenes. The JSON variant keeps the scene description human-readable with geometry in sidecar buffers, and the ecosystem — Babylon.js, Unity, Unreal, Blender and the browser engines — treats it as the native interchange format for real-time 3D.
The JSON variant of glTF is written by Blender, Khronos tooling and asset pipelines that deliberately keep the scene description readable and the binary payload separate. Babylon.js, Unity, Unreal and the browser 3D engines all treat glTF 2.0 as their interchange format.
Best for: Real-time engines, web development and 3D pipelines. There is a fuller write-up on the glTF format reference page.
Every format on this site also gets the same viewport tools: orbit, pan and zoom with fit-to-view, isometric and the six standard views, a perspective/orthographic toggle, shaded, shaded-with-edges, wireframe and X-ray display, hide-selected, and a PNG screenshot of the current view. The same controls are on the general 3D and CAD viewer, which accepts every importable format at once.
Worth knowing before you rely on it. A viewer that overstates what it can read wastes more of your time than one that is specific about its limits.
| glTF files | |
|---|---|
| Extensions | .gltf |
| Geometry | GPU-ready triangle mesh |
| Units | Meters by spec |
| Colors & materials | Full PBR materials |
| Animations | Yes |
| Typical use | Real-time engines & web pipelines |
glTF is specified in metres, while the readouts append a millimetre suffix to raw coordinates. A 2.00 mm dimension on a glTF file almost certainly means two metres.
glTF can be read and written here. Packing it into a single .glb is usually the first thing worth doing. The converter runs on the same local pipeline as this viewer, so a conversion is just as private as a preview: glTF to GLB is the usual choice.
Most likely it references a separate .bin buffer. That file is not part of what you dropped and cannot be fetched from your disk, so there is no geometry to build. Re-export as .glb, or as glTF with embedded buffers, and it will open.
The .glb, whenever you have it. It is the same scene in one self-contained binary file, so nothing can go missing. Use the .gltf here when it is the only copy you have and its buffers are embedded.
No. This is a geometry inspector: hierarchy, counts, dimensions, sections and measurements. Animation clips are not played and texture maps are not sampled — meshes are drawn in their base material color.
No. The JSON is parsed by a JavaScript loader in a Web Worker inside your browser, and Draco decoding also runs locally. Nothing is transmitted.
Geometry: gpu-ready triangle mesh. Units: meters by spec. Colors and materials: full pbr materials. Animations: yes. Of that, the viewer draws geometry and flat base colors; texture maps and animation are never displayed. glTF is specified in metres, while the readouts append a millimetre suffix to raw coordinates. A 2.00 mm dimension on a glTF file almost certainly means two metres.
Read the glTF format reference for the format itself, open the general 3D and CAD viewer if you have several formats to look at, or start from the 3D and CAD converter.
If the model is heavier than it needs to be, the mesh simplifier reads .gltf directly, decimates it in your browser and previews the result before you export. If the file is headed for a 3D printer, the G-code viewer shows the sliced toolpath layer by layer once your slicer has run.
Which 3D format should you ship on the web? A practical comparison of glTF, GLB and OBJ — file size, materials, loading speed — with free conversion tools.
GLB is the binary form of glTF — the standard format for 3D on the web and in AR. What GLB files contain, how to open them free, and how to convert to and from GLB.