Web and AR assets speak glTF; slicers speak STL. Drop a .gltf or .glb and get a printable mesh with the scene hierarchy properly resolved.
glTF was designed for real-time rendering: multiple mesh nodes, PBR materials, sometimes animation, all arranged in a scene graph. A slicer wants the opposite — one closed volume, no materials, no hierarchy. We flatten the graph, bake every node transform into the vertices, merge to a single mesh and export STL.
Watch the extension: a .gltf is JSON that points at an external .bin for geometry, so uploading it alone yields nothing. A .glb packs everything into one file — prefer it.
Assets built for rendering are frequently open shells: a chair with no underside, a mug modelled as a surface rather than a solid, geometry that looks perfect from the camera angle it was made for. That converts to a valid STL and then fails in the slicer.
If yours does, run the result through our STL repair tool — winding, duplicate vertices and small holes are fixed automatically, and the metrics tell you whether the mesh ended up watertight.
Every converter runs the same geometry engine — see all 20 conversions.