model/gltf-binary

The self-contained glTF: one .glb file packing the JSON scene description and its binary buffers into a single container, which is why it has become the interchange default for web 3D — one fetch, no dangling resource URLs. It opens with the ASCII magic glTF (the spec writes it little-endian as 0x46546C67), so a mislabeled GLB is trivially detectable. When humans need to read or diff the scene, the JSON sibling model/gltf+json is the editable form.

Defined by glTF 2.0 Specification · IANA registration. Registry facts from the IANA media-types registry via mime-db.