GLB to STL Converter
Convert a GLB file to an STL you can slice. Drop the file, see its real size in millimetres, find out if it is watertight, and download a checked STL. Nothing is uploaded.
- 1Drop the file
- 2Check it
- 3Download STL
1Drop your GLB file
Drop a .glb or .gltf file here, or choose one. It stays on your device.
Working…
This browser can't show the 3D view (WebGL is off). The check and the download still work.
Turns on when the STL has been read back and is watertight. Binary STL, millimetres.
Your file is read by this browser tab. Nothing is uploaded, and the STL is saved straight from this page.
2About this file
- Kept: the shape of every mesh, with its position in the scene.
- Dropped: colours, textures, materials and animation. STL can't store them.
- Not supported yet: Draco and meshopt compressed files. You get a clear message, and can export without compression.
3Size and direction
How to convert GLB to STL
- Drop the GLB. A .gltf file works too if its data is built in.
- Check the size. GLB is in metres, so a model made for the web or a game can come out far too big or too small to print. Type the longest side you want in millimetres.
- Read the check. It lists open edges and non-manifold edges. Turn the model with the 90° buttons if it lies on its side: GLB is Y-up and printers are Z-up, so this page turns it upright first.
- Download the STL. The button turns on when the file passes.
Why a GLB might not be watertight
GLB is made for showing models on screens, so nothing requires it to be a closed solid. Models from AI generators and 3D scans often have thin shells, loose parts and small holes, and game models often have separate pieces that overlap. A slicer needs a closed surface to know what is inside. A GLB can look perfect on screen and still fail here.
What the check proves
The download button starts off. The page writes the STL, reads those bytes back the way another program would, joins corners that match to 0.0001 mm, and only turns the button on if every edge joins exactly two faces and the size matches. If it doesn't pass, you see how many open and non-manifold edges there are, and you can run the simple repair. The repair closes holes and turns faces, and it can change the shape, so it only runs if you press it. Some files can't be fixed this way, and those need Blender or MeshLab. The check is about the file, not about how it will print.
Scale: from metres to millimetres
The glTF 2.0 format defines its units as metres, and STL has no units, but slicers read STL numbers as millimetres. So a 0.05 unit GLB is 50 mm, and that is what this page writes. Generated models often come out about one or two units across, which means 1 to 2 metres, so set the longest side before you download.
FAQ
How do I convert a GLB file to STL?
Drop the GLB on this page, check the size and the watertight result, and press Download STL. There is no account, and the file stays on your device.
Can you 3D print a GLB file?
Slicers need a closed mesh, and many only take STL, 3MF or OBJ. Convert it here first. If the GLB is not watertight, the page shows where it fails and offers a simple repair.
Does GLB to STL keep colours and textures?
No. STL stores only the shape, so colours, textures and materials are dropped. For a multi-colour print you would need a format such as 3MF and a slicer that paints colours.
Why does my converted model come out huge or tiny?
GLB files are in metres and many are not made at real-world size. Type the longest side in millimetres under Size and the STL is scaled to it.
Why is the download button off?
The mesh isn’t watertight, or it failed the read-back. The check lists the problem. Try the simple repair, or fix the model in Blender or MeshLab and export it again.
My GLB says it uses Draco compression. What now?
This page can’t decode Draco or meshopt yet. Export the GLB again with mesh compression turned off, for example in Blender’s glTF export settings.