Tools · GLB Viewer

GLB and glTF Viewer: see what is inside the file

Drop a GLB or a glTF with its .bin and images. Besides the model and its animations the viewer shows how many triangles, materials and textures it has, how the file size splits into scene data, geometry and images, and which compression and extensions it uses.

The GLB never leaves the browser

Drop a GLB or glTF here

GLB, or glTF with its .bin and textures, a folder or a ZIP

Try:

Parsing, Draco and KTX2 decoding run locally. Not a single byte of the model is uploaded.

What are GLB and glTF?

glTF 2.0 is an open format by the Khronos Group, made for loading 3D content quickly in apps and on the web. It uses physically based materials (base colour, metallic, roughness, normal, occlusion, emissive), supports skeletons, morph targets and animations, and is also published as the ISO/IEC 12113 standard.

A .gltf file is JSON that points to binary buffers (.bin) and texture images next to it. GLB is the same content in one binary container: a short header, a JSON chunk and a binary chunk with geometry and images. Extensions add features on top, for example Draco or Meshopt for smaller geometry and KTX2 for textures that stay compressed on the GPU.

What the glTF tab shows

Key figures: Triangles, materials, textures, draw calls, nodes, animations, estimated texture memory and the file size in one grid.
Size breakdown: How many bytes go to the JSON scene description, to geometry and animation buffers and to embedded images. The usual first step when a GLB is too heavy.
Compression check: Draco, Meshopt, mesh quantization, KTX2, WebP and AVIF are recognised and explained, required extensions are marked.
Animations: All clips with duration, ready to play, plus morph target sliders in the Animation tab.

Programs that open GLB and glTF

Blender: Ships with a glTF importer and exporter. Draco compressed files can be imported as well.
three.js, Babylon.js, model-viewer: Web libraries with glTF as their main format. They read Draco, Meshopt and KTX2 when the decoders are set up.
Godot: Imports GLB and glTF natively. Draco compressed files are not supported there, so keep an uncompressed copy.
Unity and Unreal Engine: Unity reads glTF through the glTFast package, Unreal Engine through its glTF importer.

Common GLB problems and fixes

The engine refuses the file: Look at the required extensions in the glTF tab. A program without a decoder for Draco, Meshopt or KTX2 cannot open a file that requires it. Export again without compression or keep two versions.
A .gltf loads without geometry or textures: Its .bin buffer or images were left behind. Drop the whole folder or a ZIP. The viewer names the missing buffer.
The file is much larger than expected: Check the size breakdown. Large embedded images are the usual cause and shrink well with WebP or KTX2, heavy geometry needs Meshopt, Draco or fewer triangles. The GLB Optimizer does both.
Materials look different than in the original program: glTF only knows its PBR model plus official extensions. Procedural shaders, node setups and special effects from Blender or other tools are baked down or lost on export.

Frequently asked questions

What is the difference between GLB and glTF?

Same data, different packaging. glTF is a JSON file with separate .bin and image files, GLB puts all of it into one binary file that is easier to share.

How can I tell if a GLB uses Draco compression?

Open it and check the glTF tab. KHR_draco_mesh_compression appears under compression, marked as required if the geometry can only be read with a Draco decoder.

How do I make a GLB file smaller?

First find out where the bytes are with the size breakdown. Then use the GLB Optimizer to compress textures, add Meshopt or Draco and reduce polygons where needed.

Can I see the animations of a GLB?

Yes. Clips appear in the glTF tab with their length and start with a click. The transport bar pauses them, scrubs through them and changes their speed.

Does the viewer check whether my GLB is valid?

It shows what three.js can read and points out missing files, extensions and scale problems. It is not a full validator against the glTF specification, for strict checks use the official glTF Validator by the Khronos Group.