GLB to STL converter

1. Drop your GLB (or a .gltf with its files) above.
2. Check the size. glTF is in metres, so it's converted to millimetres automatically. Most AI models come out at an arbitrary size, so type the height or width you want.
3. Check that it's watertight and that thin parts aren't too thin.
4. Download an STL, one STL per part, or a 3MF that keeps each part's base colour.

glTF is the standard format for 3D on the web. GLB is the single-file version: geometry, materials and textures packed together. A .gltf file is the same thing split into a text file plus separate .bin and image files. Drop them all together and they'll load.

• Units are metres and +Y is up, by definition. The tool converts to millimetres and stands the model upright for printing automatically.
• Materials are physically based (metal, roughness, colour). The preview shows them under realistic lighting.
• Compressed files work: geometry packed with Draco or meshopt is decoded in your browser.

Models from AI generators and game asset stores are made to look good on screen, not to print. Watch for:

• Holes and open surfaces. The watertight check shows them. Small ones are repaired by most slicers.
• Zero-thickness parts such as hair strands, leaves or capes. They can't print and need thickening in a 3D editor.
• Many separate pieces. The number of pieces is shown; overlapping pieces are usually fine, because slicers merge them.
• Colours come from textures. STL has none; the 3MF keeps one base colour per part.

A mesh is watertight (or “manifold”) when it encloses a solid with no gaps: every edge is shared by exactly two triangles, and all faces point outwards. Slicers need that to know what's inside and what's outside. The check here reports three kinds of problem:

• Open edges: holes in the surface.
• Non-manifold edges: three or more faces meeting at one edge, common where parts overlap.
• Flipped faces: triangles facing the wrong way.

Small problems are common and most slicers repair them automatically when they load a file. For the rest, Repair STL fills holes and turns flipped faces around; overlapping parts and surfaces with no thickness (typical of game assets and some AI-generated models) need a 3D editor. When a mesh isn't closed, its volume is shown as approximate.

UltiMaker Cura imports GLB and glTF. Bambu Studio's 2.7 beta added a texture-to-colour feature for OBJ and glTF files, without Draco support. PrusaSlicer and OrcaSlicer don't list glTF among their formats. Converting here works with every slicer and lets you fix size and orientation first. If the STL turns out too heavy for your slicer or for Tinkercad, reduce its triangles.