Browser-local converter
glTF to STL converter
Convert a .gltf scene into a printable STL without uploading anything. A .gltf is the JSON form of glTF and usually keeps its geometry in a separate .bin file, so add both to the queue and the pair is read together.
Drop your glTF files here
STL, OBJ, PLY, GLB, glTF, 3MF, SVG and DXF. Nothing is uploaded: files are read and converted inside this tab. Checking what this device can handle...
Queue
No files yet. Drop models above, or use the file picker.
Output
Units
Size and placement
Repair and cleanup
These can change the shape, so they need a before-and-after review before export.
Inspection
Add a model to see its dimensions, mesh health and estimated volume.
What this glTF to STL conversion does and does not do
- A .gltf normally references an external .bin buffer. Add it to the queue alongside the .gltf. Nothing is ever fetched over the network to resolve a reference, so a missing buffer is reported rather than downloaded.
- glTF is defined in metres and STL has no unit, so a 0.2 m model becomes the bare number 0.2, which slicers read as 0.2 mm. Convert the unit in the workspace before exporting.
- The whole scene graph is flattened into one STL shell. Node names, hierarchy, cameras and lights do not survive, because STL has nowhere to record them.
- Materials, textures, vertex colours and uv coordinates are all dropped. STL stores geometry and nothing else.
- Draco and meshopt compressed geometry cannot be decoded here and is refused with a clear message rather than partly read.
- Point and line primitives are skipped, because they are not surfaces and cannot be printed. The workspace reports how many were left out.
Troubleshooting
It says the buffer is missing
The .bin file the .gltf references was not in the queue. Add it with the same filename the .gltf expects. A glTF with an embedded base64 buffer, or a .glb, works on its own.
The print is microscopic
The metre-versus-millimetre problem. glTF measures in metres, so convert the unit to millimetres in the workspace, or use scale-to-size to set a real dimension.
Part of the scene did not convert
Only triangle geometry can become an STL. Point clouds, lines, cameras and lights are skipped and counted, and Draco-compressed meshes are refused outright.
The mesh is inside out in my slicer
Run safe repair. It makes triangle winding consistent across each closed shell and orients the shell outward using its enclosed volume.
Questions
Should I use .gltf or .glb?
GLB if you have the choice, because everything is in one file and nothing can be separated from it. Both are read here; .gltf just needs its .bin supplied.
Is the geometry exact?
Yes, to float precision. Node transforms are applied with a proper inverse-transpose for normals, and mirroring transforms have their winding corrected so outward faces stay outward.
What if the buffer is embedded in the .gltf as base64?
That works on its own, with no second file needed. A data URI buffer is decoded in place, which is why some .gltf files open here immediately and others ask for their .bin.