GLB Viewer

A GLB is a single file, so there is nothing else to select. Drop it on the panel above, or press Open 3D file(s) and choose it.

1. 1

   Open the file

   The scene is parsed and framed to fit. A model with several 4K textures takes a moment longer than the geometry alone, because the images are decoded before the first frame.

2. 2

   Read the panels

   Overview gives meshes, triangles, vertices and the bounding box. Materials lists each material, its type and every populated texture slot.

3. 3

   Check the animation

   Animations lists every clip with its duration. Select one to play it, pause it, or change the speed to 0.5×, 1× or 2×.

Export PNG saves the current view at 1× or 2×, on the stage colour or with a transparent background.

A GLB is a binary container around a glTF scene. A 12-byte header is followed by chunks: the first is JSON and describes nodes, meshes, materials and animations; the second is binary and holds vertex data, animation samplers and, in most files, the images. The JSON points at buffer views inside the same file, which is why a GLB needs neither a .bin nor a texture folder.

It can still point outside. An image described by a URI instead of a buffer view is resolved from the files selected with the model, and the usual name rules apply. A GLB that embeds everything never has this problem, which is the reason the format exists.

Materials lists each material by the name in the file, the three.js type it becomes, and the texture slots that are populated: base colour, normal, roughness, metalness, emissive, ambient occlusion and the rest of the standard set. Each slot shows the image size and a thumbnail. A material with no maps is normal for a flat-shaded asset.

Animations lists every clip with its name, duration and track count. The transport plays the selected clip, pauses it, and switches the speed. A clip that exists but barely moves the model is still listed: the panel reports what the file declares, not what the animation looks like.

Draco and meshopt compress geometry, not textures. Both decoders are served from this site and downloaded only when a file needs them, so an uncompressed GLB never pays for them.

A file that requires Draco (KHR_draco_mesh_compression) or meshopt (EXT_meshopt_compression) opens like any other GLB. A file that requires an extension the viewer does not implement is refused by name instead of rendering a partial scene, and the extension id is printed with the reason.

KTX2 textures are not supported in this viewer.

• Black or grey surfaces

  Usually a texture that did not decode, or a material whose maps are missing. Materials shows which slots hold an image, and Issues names a file that could not be resolved.

• No textures at all

  The file may reference images by URI that were not selected with it. A GLB that embeds its images never has this problem.

• No animation

  Plenty of files that look animated in a DCC tool contain a single rest pose. When the file declares no clips, the panel says so; that is a property of the file, not a player failure.

• Different colours than in the editor

  The viewer renders the glTF material model, not a DCC shader graph. A fully metallic material has no environment to reflect here, so it can look darker than in an engine.

GLB packs the JSON, the buffers and the images into one file. glTF keeps the scene apart from its resources, so a pipeline can share a buffer or swap textures without rewriting the scene. A file that has to arrive in one piece is usually GLB; a file produced by a build step is often glTF.

The glTF viewer for external buffers and textures covers the split case, including the list of files a .gltf expects beside it.