glTF (GL Transmission Format)

glTF is the Khronos Group’s open standard for delivering 3D models, often called “the JPEG of 3D”. A .gltf file is JSON that describes meshes and physically based (PBR) materials, with binary data and textures alongside or embedded.

Used by: three.js, Babylon.js, Blender, Sketchfab, and developers who want a readable, editable model file.