Convert glTF to STL
Convert glTF to STL in your browser. The conversion runs on this page and the file never leaves your computer.
Result
Before you convert: what this keeps and what it destroys
Preserved
- The geometry, triangle for triangle
- Overall dimensions and proportions
- Watertightness, where the input is watertight
Destroyed
- A recorded unit: STL stores none
- Colour
- The separation between parts, merged into one body
- Animation, rigs, cameras and lights, if the file has them
↺ the reverse: STL → glTF · about .gltf · about .stl · just view it instead
Why people convert glTF to STL
Printing an asset that came out of a web or AR pipeline, where glTF is the native currency and slicers have never heard of it.
Everything glTF is good at is discarded here, because STL holds none of it: the node hierarchy flattens to one body, materials and colours go, and the unit declaration has nowhere to live.
The scale is handled and it is the part that would otherwise ruin the print. glTF is metres by specification and STL is read as millimetres, so coordinates are multiplied by 1000. Without that a 0.05 m part would arrive as a 0.05 mm speck. If your .gltf references an external .bin, upload the GLB instead; a single-file upload cannot reach the geometry.
What you get
You get a binary STL file containing the same triangles the glTF file described. No geometry is added, removed or approximated: mesh-to-mesh conversion is a change of container, and this site's tests check that the triangle count comes out identical.
Not carried across by this conversion: a recorded unit, colour, the assembly structure.
The conversion runs in your browser. Your file stays on your computer and is not uploaded.
What to check afterwards
- glTF and GLB use metres by specification. This converter interprets the source coordinates that way. If the model was authored at a different scale, confirm a known dimension before using the output.
- The numbers change. STL is read in millimetres and glTF in metres, so every coordinate is rescaled. The result is the same physical size, but the numbers in the file are different numbers.
- Colour is lost. STL has nowhere to store it. If colour matters, pick a target that keeps it: 3MF, GLB, PLY or USDZ.
- Separate parts merge into one body. glTF can describe an assembly and STL cannot, so a multi-part model arrives as a single mesh. 3MF and GLB both keep the structure if you need it.
- Coordinates are stored as 32-bit floats. For a part measured in millimetres that's far finer than any machine tolerance. For a model spanning hundreds of thousands of units it isn't.
If you need something this conversion cannot give you
If the unit has to be unambiguous, convert to 3MF instead. It records the unit in the file, so nobody downstream has to assume millimetres and nobody has to scale by 25.4 after the fact.
If colour has to survive, convert to 3MF for printing, GLB for the web, or PLY if the colour is per-vertex scan data.
If the parts must stay separate, convert to 3MF or GLB. Both keep a real structure, so a five-part assembly arrives as five parts rather than one merged body.
If your slicer accepts 3MF, consider it when you need a unit declaration or separate components in the output. Keep the original project for its print settings.
Going the other way
Convert STL back to glTF. The reverse conversion also works with mesh geometry. It does not reconstruct exact CAD surfaces. Material data and part structure lost in either direction cannot be restored by converting back. Keep the original file for later edits.
How we know this conversion works
This pair was checked against 1 file from the test corpus on 2026-09-04. Each run parses its own output back in and compares the bounding box, the triangle count and, for closed solids, the volume against the input.
A pair that fails those checks doesn't get a page. That's why this site lists 120 conversions and not the several hundred a format-times-format grid would suggest.