AI 3D generators like Meshy, Tripo, and Luma export models as GLB (binary glTF) — the standard format for web viewers and AR. But if you want to 3D-print that model, you need STL — the format every slicer understands.
Most online converters upload your file to a server. If you're working with proprietary models or just value privacy, that's a dealbreaker.
I built STL Mesh, a browser-based converter that runs entirely on the client. Your file never leaves your device — the conversion happens in a Web Worker using three.js.
GLB parsing: The three.js GLTF reads the binary container, extracting mesh geometry, node transforms, and scene hierarchy.
Transform baking: Each mesh's transform chain is flattened to world space. A GLB scene can have nested nodes with translation, rotation, and scale — all of that gets baked into final vertex positions.
STL encoding: The STLExporter writes binary STL at 50 bytes per triangle: a normal vector (3×float32) + three vertices (9×float32) + an attribute byte count (uint16). No materials, no textures — just triangles.
This catches everyone at least once: glTF counts in meters, but slicers assume STL numbers are millimeters. A model that's 0.05 units in GLB (5 cm) becomes 0.05 mm in your slicer — invisible.
The converter shows the bounding box dimensions so you can spot this before down. If your numbers look 1000× too small, scale by 1000 in the slicer.
The same architecture handles other format pairs:
| From | To | Use case |
|---|---|---|
| GLB → STL | Print AI-generated models | |
| OBJ → STL | Print sculpts and scans | |
| FBX → STL | Print game/animation assets | |
| 3MF → STL | Extract mesh from slicer projects | |
| STL → GLB | Put print files on the web | |
| STL → USDZ | iOS AR Quick Look | |
| SVG → STL | Extrude logos into 3D prints |
All converters at stlmesh.com. Drop a GLB on the converter page, check the bounding box, download the STL, open it in your slicer. The whole flow takes about 10 seconds.
If you're building something similar, the key libraries are:
three.js GLTF / STLExporter
Built by Casey Marlin. Feedback and feature requests welcome.