GLB and glTF in one paragraph
glTF 2.0 is a Khronos Group standard, and GLB is the binary container of the same data: one file with the mesh, materials and images packed together. The text form is a .gltf file that points to a .bin buffer and image files, or carries the buffer inside. In glTF, one unit is one metre.
What this GLB file viewer has been tested on
- Plain GLB and glTF, including text glTF with a .bin and with an embedded buffer.
- Draco-compressed GLB and glTF: a cube and a 9,024-triangle sphere decode to the same size and volume as the uncompressed originals.
- A Draco GLB exported by Blender with 21,696 triangles (gears), which opens and converts to STL, OBJ and glTF.
- The Khronos sample Box, plain and Draco.
The Draco decoder (337 KB, 100 KB gzip) comes from our domain and loads only when a compressed file opens. Textures are read by the engine but are not covered by our tests yet.
Units: why a GLB part looks a thousand times off
glTF viewers treat one unit as one metre. A maker who exports a 20 mm bracket as raw numbers gets a file that other glTF viewers show as 20 m. This viewer shows the raw numbers as millimetres, which is what print files expect. When we save GLB, 1 unit in stays 1 unit out, so the numbers do not shift.
If a downloaded figure is tiny or huge, scale it to an exact size on one axis with Edit, then save. The scale STL page walks through it.
Open a glTF with its companion files
- Press Open File and select the .gltf, its .bin and the images in one go.
- Check that the parts count and the size in Info look right.
- If the model stands on its side, tick "Rotate Y-up model to Z-up" when you convert.
A single .glb needs no companions, since everything is packed inside.
From GLB to a printable file
Most GLB models were made for screens, so run the mesh check before printing. Then GLB to STL gives a slicer file, and GLB to OBJ suits editing software. Going the other way, STL to GLB makes a part easy to show on a web page. Saving with Draco compression is not offered. For game assets and plain meshes, the FBX viewer and the OBJ viewer work the same way.
Questions and answers
How do I open a GLB file on Windows or a Chromebook?
Open this page in Chrome or Edge and drop the file. Nothing is installed, and the model is decoded in the tab.
Can I preview a GLB file online from a link?
Yes, with a ?url= link to a file whose server allows the download, or with the Chrome extension's right-click Open in STL Viewer.
Does the viewer play GLB animations?
The tests cover the mesh, its size and its conversion. Animation playback is not part of them.
Why does my converted GLB look huge in another viewer?
That viewer reads the numbers as metres. A 20 mm part saved as raw numbers shows as 20 m there; scale it down to metres before export if the target is a glTF scene.
What is the GLB file size limit?
There is no fixed cap. Memory decides: a million triangles open in 5 to 12 s, and above roughly 1 to 2 million the tab may run out of memory.