Free STL (.stl) to glTF (.gltf) converter — running entirely in your browser. No upload, no signup, no file limits: your files never leave your device.
STEP · IGES · BREP · STL · OBJ · PLY · GLB · glTF · 3MF · COLLADA · AMF · FBX · 3DS · OFF · LAS · PCD · XYZ · PTS
STL is the de-facto standard for 3D printing. It describes a model purely as a mesh of triangles — no color, no units, no assembly structure — which makes it simple, universally supported, and the required input for virtually every slicer, from PrusaSlicer and Cura to resin-printer tools.
glTF is the Khronos royalty-free standard for transmitting 3D scenes. The JSON variant keeps the scene description human-readable with geometry in sidecar buffers, and the ecosystem — Babylon.js, Unity, Unreal, Blender and the browser engines — treats it as the native interchange format for real-time 3D.
| STL | glTF | |
|---|---|---|
| Geometry | Triangle mesh | GPU-ready triangle mesh |
| Units | No — unitless numbers | Meters by spec |
| Colors & materials | No | Full PBR materials |
| Animations | No | Yes |
| Typical use | 3D printing | Real-time engines & web pipelines |
Yes — free with no accounts, no watermarks and no file-size limits. Conversion runs on your own machine, so there are no server costs behind it.
No. The converter runs entirely in your browser using WebAssembly. Your .stl file never leaves your device, which makes it safe for confidential designs.
Yes — parts and assembly hierarchy are preserved where glTF supports them, and you can optionally merge everything into a single mesh during conversion.
Yes. Every converted model opens in the built-in 3D viewer with an assembly tree, display modes and section views, so you can inspect the result first.
STL already contains only unitless triangles, with no part names, colors or design history for a converter to preserve. The glTF result contains the converted geometry, hierarchy and flat colors, but it cannot recreate texture maps or animation that were dropped on import.
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