Model Explorer at 0xr.space reads these glTF 2.0 extensions in a browser, on an Android phone and on Meta Quest: KHR_draco_mesh_compression, EXT_meshopt_compression, KHR_texture_basisu, KHR_mesh_quantization, KHR_texture_transform, KHR_materials_transmission with KHR_materials_volume, KHR_materials_sheen, KHR_materials_clearcoat, KHR_materials_specular, KHR_materials_ior, KHR_materials_emissive_strength, KHR_materials_unlit, KHR_materials_pbrSpecularGlossiness, and VRM 0.x and 1.0 with MToon and spring bones. The decoders for Draco, meshopt and KTX2 are fetched only when a file uses them, and the same loader runs in the Quest browser, the Model Explorer app and a desktop browser, so a file behaves the same in all three.
Not read: KHR_lights_punctual, KHR_materials_variants, EXT_mesh_gpu_instancing, KHR_materials_anisotropy, KHR_materials_iridescence and KHR_materials_dispersion. KHR_materials_diffuse_transmission is drawn as transparent. Clearcoat uses its factors, not its textures, and a texture transform that switches to a second UV set is not applied. An extension it does not read never stops a file opening, even one marked required.
No. The model is drawn without that extension rather than refused.
No. KHR_lights_punctual is not read; the model is lit by the app's own lighting.
No. The model's default materials are shown.
No. It is read on the device, and nothing is sent to a server unless you create a share link yourself.