STEP to STL converter

Drop a STEP file, check the preview, download STL. The conversion runs in your browser, so your model never leaves your device.

Convert the attached STEP file to STL

Files are processed entirely in your browser. Nothing is uploaded to a server.

Any 3D edit is just a prompt away.
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How the conversion works

STEP (.step / .stp) is a CAD exchange format that describes exact surfaces such as cylinders, fillets, and splines instead of triangles. FreeCAD, Fusion, and SolidWorks all export it.

The converter writes binary STL, which is what slicers expect. Drop the result straight into Bambu Studio, PrusaSlicer, Cura, or any other slicer.

The conversion runs Open CASCADE, the same geometry kernel FreeCAD uses, compiled to WebAssembly. Your CAD surfaces are tessellated into a watertight mesh right in the browser tab.

Frequently asked questions

Does my file get uploaded?

No. Parsing and export run in your browser with WebAssembly and three.js. The file stays on your device, and it works offline once the page has loaded.

What survives the STEP to STL conversion?

Exact CAD surfaces become triangles at a fixed resolution. That step is one-way: the mesh can't be turned back into parametric CAD. Dimensions are preserved, so the part prints at the right size.

Does it handle assemblies?

Yes. All bodies in the STEP file are merged into one mesh. If you need the parts separated, export them individually from your CAD tool, or cut the result with the split tool afterwards.

Is there a file size limit?

Files up to 300 MB and 8 million triangles work. Heavier meshes take longer rather than failing outright; if a file is unwieldy, reduce its triangle count first with the reduce tool.

More STEP conversions

STEP → OBJ STEP → GLB All converters

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