GLB and glTF are the same 3D format in two different containers. glTF (.gltf) is JSON text that usually points to separate binary and image files, while GLB (.glb) packs the geometry, materials and textures into one self-contained binary file. Both open in the GLB viewer and the glTF viewer.
Here is what that means in practice.
The same standard underneath
glTF (GL Transmission Format) is an open standard, sometimes called “the JPEG of 3D”, designed for efficient loading in browsers, games and AR. GLB is not a different format, it is glTF saved in a binary wrapper. So a model in either container describes exactly the same scene; only the packaging differs.
glTF: text plus companions
A .gltf file is human-readable JSON. It describes the scene and references the heavy data, the mesh geometry in a .bin file and textures as separate images. This is convenient while you are building a model, because you can open the JSON or swap a texture without repacking everything. The catch: to use the model, you need all the referenced files together.
GLB: everything in one file
A .glb file bundles the JSON, the binary data and the textures into a single file. There are no companions to lose, which makes GLB the easy choice for sharing a model, emailing it, or putting it on a website. Most pipelines author in glTF and export GLB as the final, shippable file.
Which should you use?
- Sharing or deploying a finished model? Use GLB. One file, nothing to misplace.
- Editing or iterating? glTF with separate files can be handier mid-workflow.
- Putting it on the web or in a game engine? GLB is the common, reliable choice.
Open either one
You do not need to convert anything just to look at a model. Drop a .glb or a self-contained .gltf into the GLB viewer to rotate it, check its size and triangle count, and grab a screenshot, all locally, with nothing uploaded.