STL to STEP converter
Free, in your browser, no account.
Your file stays in your browser. Nothing is uploaded.
How it works
- Drop your STL on the box above, or click to choose it. It stays on your computer.
- Check the preview and the line under it: it tells you whether you got a solid or a faceted surface model.
- Click Download STEP and import the .step file into your CAD program.
Questions
Is it free?
Yes. Converting and downloading are free, with no account and no sign-up.
Is my file uploaded?
No. The conversion runs in your browser and the file is never sent to us. We count anonymous usage, such as how many triangles a file had and how long it took, never the file or its name.
Will I be able to edit the STEP file?
A solid STEP holds one closed solid, like the STEP files CAD programs export. It has your STL's exact shape, so curved surfaces stay faceted: nothing is turned back into true cylinders or curves. A faceted surface model is a set of flat triangles, not a solid: fine to view and import, not to edit as a solid.
Why did I get a faceted model instead of a solid?
A solid needs a watertight STL: every edge shared by exactly two triangles, every facet facing outward, and no part of the surface crossing another. For now, solids are made from STLs of up to 20,000 triangles. Anything else becomes a faceted surface model, so you still get a STEP file.
How large can my file be?
Up to 200,000 triangles, about a 10 MB binary STL. Larger meshes make STEP files that are slow to open. Reduce the triangle count in your mesh tool first.
Which programs open the file?
It is a standard STEP file (ISO 10303-21, AP214). We check every kind of file the converter makes by reading it back with an independent STEP reader and by importing it into WebCAD.
Can I convert STEP to STL?
Yes, with the STEP to STL converter.