GLB is a binary glTF container that can package scene JSON, binary buffers, and images into a single file.

Extension
.glb
Standard
glTF 2.0
Container
JSON + binary data
Common use
Web, preview, interchange

GLB versus glTF

glTF can be a JSON file with separate buffers and textures. GLB provides a binary container that is easier to move as one file. Both describe the same core scene model.

Inspect before publishing

Check geometry counts, texture dimensions, compression extensions, materials, animations, bounds, and final transfer size against the destination budget.