How to convert GLB to STL
- Drop your .glb file into the box above, or click Choose file.
- Check the 3D preview, size and triangle count.
- Make sure STL is selected as the output format. Adjust scale or up-axis if needed.
- Click Download. The .stl file is created instantly on your device.
Why convert GLB to STL?
GLB is common for web and AR models, while 3D printers need STL. The converter takes all meshes in the scene, applies their transforms and writes them into one STL. Textures and materials are dropped because STL has no colour.
What changes in the conversion
- Textures are dropped. STL cannot store image textures.
- Up-axis. GLB is Y-up while STL is usually Z-up; the model is rotated so it stands the right way up. Untick "Convert up-axis" to keep the raw coordinates.
- Animation and rigs are not exported. The model is written in its rest (bind) pose.
- Geometry is preserved. Every triangle, with all object transforms applied, ends up in the new file.
GLB vs STL
| GLB | STL | |
|---|---|---|
| Full name | binary glTF | Stereolithography |
| Stores | geometry, materials, textures, hierarchy and animations | geometry only |
| Colour | Yes | No |
| Textures | Yes | No |
| Units | metres by specification | none – most programs read STL numbers as millimetres |
| Exact CAD geometry | No | No |
About the formats
GLB (binary glTF) was defined by the Khronos Group as the single-file binary form of glTF 2.0. It packs meshes, PBR materials, textures, scene hierarchy and animations into one compact file. It is the standard for 3D on the web, AR viewers, e-commerce product views and game engines.
STL (Stereolithography) was created by 3D Systems in 1987 for its stereolithography printers. It describes only the surface of a model as a list of triangles, without colour, materials or units. It is the default file for 3D printing and the format almost every slicer (Cura, PrusaSlicer, Bambu Studio, Chitubox) opens.
Frequently asked questions
Is this converter free?
Yes. You can convert GLB to STL for free – up to 3 conversions a day, with no sign-up and no watermark. If you need more, Pro gives you unlimited conversions and batch conversion (free for 7 days).
Are my files uploaded to a server?
No. The conversion runs entirely in your browser using WebAssembly and JavaScript. Your model never leaves your computer, which also makes it safe for confidential parts and patient data.
Is there a file size limit?
There is no fixed limit. Files of a few hundred megabytes work on a typical laptop; the practical limit is your device's memory.
Why was my model tiny in the slicer?
glTF and GLB use metres, slicers read STL as millimetres. A 20 cm figure is 0.2 units in a GLB – which becomes 0.2 mm. The converter detects small models and suggests "Metres → millimetres" scaling automatically.
Why is my model lying on its back?
GLB is Y-up, STL files for printing are usually Z-up. Keep "Convert up-axis" ticked and the model will stand upright on the build plate.