GLB to STL: from a web model to a print
GLB is the binary container of glTF 2.0, the Khronos Group standard used for 3D on the web. Besides meshes it can hold materials and textures. STL keeps only the triangles of the surface, which is exactly what a slicer reads.
| In the GLB | In the STL |
|---|---|
| Meshes, Draco-compressed or plain | Triangles, same count |
| Materials, textures, animation | Gone; STL has no place for them |
| Coordinates | Raw numbers copied 1:1 and read as mm |
Draco-compressed GLB opens here
Many web exports compress meshes with Draco. Here the Draco decoder (337 KB, 100 KB gzip) loads from this site only when a compressed file is opened.
A Draco GLB of gears exported from Blender, 21,696 triangles, converted to STL and re-opened with the same size, volume and triangle count. A Draco cube came out matching its uncompressed original too.
Meters, millimeters and the right way up
glTF counts in meters, so a 20 mm part is often stored as 0.02. The STL keeps that number and the viewer shows 0.02 mm. Open Edit → Size and type the real length of one axis in mm; the other two follow.
Models from glTF usually stand Y-up, which puts them on their back in a slicer. Press Other formats and tick Rotate Y-up model to Z-up (for slicers), then save the STL from there.
How to convert a GLB file to STL
- Drop the .glb, or a .gltf with its .bin and textures. Several files can go in together.
- Read the bar:
name.stl, its size and Download STL. - Check Info. The mesh check tells you if the model is watertight, which web models often are not.
- Fix the size in Edit → Size and the orientation with the Z-up option.
- Press Download STL, or Convert another file for the next model.
The GLB is decoded and converted by code in this tab; the test run counted 0 requests to other domains.
Check the part in the same tab
The converted model stays in the viewer, so you can test it before the download. Measure snaps to vertices and shows the distance with ΔX, ΔY and ΔZ; on the test cube two corners read exactly 20.00 mm.
The section plane cuts along X, Y or Z and paints the inside red, which shows thin walls in a figurine. Info gives volume and the weight for 17 materials, PLA at 1.24 g/cm³ among them.
Troubleshooting a GLB that will not print well
- Info shows many parts. Web assets are often built from separate shells that overlap. After Edit → Repair, Combine with union of all parts makes one body.
- A plane or leaf is paper-thin. Some web models are single surfaces with no thickness, which a slicer cannot fill. Model a thickness in a 3D program; this tab has no wall-thickness tool.
- The file stays gray in the slicer. That is expected: textures do not travel into STL. Pick the filament color in your slicer.
Before you print the converted GLB
Run STL repair if the mesh check finds holes, then price the part in the 3D print cost calculator. If the model is meant for a modeling program instead, GLB to OBJ fits better. The way back is STL to GLB, and the GLB viewer opens the file just to look.
Questions and answers
Can you convert GLB to STL?
Yes. Open the .glb on this page and press Download STL. Plain and Draco-compressed GLB both work.
Why is my STL only 0.02 mm big?
The GLB was built in meters. Set the true length in Edit → Size; the STL is written in the new size.
Do the textures of the GLB come along?
No. STL stores the surface only. Color for the print is chosen in your slicer.
Can I convert a .gltf with a separate .bin file?
Yes. Drop the .gltf, the .bin and the images together, and the converter reads them as one model.
Why does the model lie on its side in the slicer?
The model is Y-up and slicers are Z-up. Tick Rotate Y-up model to Z-up under Other formats before saving.
Is the GLB uploaded for the Draco decoding?
No. The decoder is downloaded from this site once and runs in your tab; the model itself stays on your device.
Can I print a GLB I downloaded from a web store?
Technically yes, once it is converted and closed. Check the license of the asset first, then run the mesh check, because store models are built for screens and are often open or paper-thin in places.