How to convert glTF to STL
- Drop your .gltf 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 glTF to STL?
A .gltf file is often accompanied by a .bin and texture images. Select all of them together (or drop them at once) so the geometry buffer can be read; the converter then writes an STL ready for slicing.
What changes in the conversion
- Textures are dropped. STL cannot store image textures.
- Up-axis. glTF 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.
glTF vs STL
| glTF | STL | |
|---|---|---|
| Full name | GL Transmission Format | 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
glTF (GL Transmission Format) was published by the Khronos Group (version 2.0 since 2017). It is a JSON scene description that references binary buffers and textures, either as separate files or embedded. It is the "JPEG of 3D" – the most common format for real-time 3D on the web and in engines like three.js, Babylon.js and Unity.
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 glTF 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.