STEP to STL — turn a CAD file into a printable model
Convert STEP (.step, .stp) or IGES to STL for 3D printing: every body of the CAD file as its own part, curves fine enough to print smooth. Repair, cut and check the size on the way. Nothing uploaded, no account.
Saves model files for your slicer, never printer code. Opened and sliced in PrusaSlicer, OrcaSlicer, Bambu Studio and Cura.
About this conversion
A STEP file keeps exact curved surfaces; a printer needs triangles. The surfaces are split by OpenCascade, the same geometry kernel FreeCAD and PrusaSlicer use, no further than 1/2000 of the part’s size from the true surface — a 20 mm part to within 0.01 mm. Every body in the file opens as its own part, in the place the drawing put it, in millimetres. Before saving you can check that each part is a closed solid, cut it, combine it with other parts or lay it on the bed on the face it should print on.
Just want to look inside it?
The same tool without converting anything: open the file and read it.
The same model, other ways
The model stays open after it is read, so the format is picked at the end: the same model can leave here as 3MF (.3mf) or OBJ (.obj). Before that you can repair it, cut it, make it smaller or combine it with another one.
Questions
- Does it read assemblies?
- Yes, when the parts are inside the file. An assembly saved as a list of other STEP files has nothing to read on its own — open the part files instead.
- Is anything uploaded?
- No. The STEP reader runs in your browser; the first STEP file you open loads it (about 8 MB).