Convert STEP and STP CAD files to STL free in your browser. The part keeps its true size; edit or combine it, then export a print-ready STL or 3MF.
Drag your .step or .stp file into OwlCAD in your browser. It opens as meshes, one per part, in its own units; check the dimensions, then click Export and save it as STL, a CAD part ready for your slicer. There is nothing to install.
Open the STEP a supplier or colleague sent you and print it without desktop CAD.
STEP records its units, so the part arrives at its real size in millimetres, with none of the scale errors unitless meshes bring.
Resize it, combine and cut it with other shapes (union, subtract, intersect), or add a mounting plate, all in the same browser tab.
Run the print check for wall thickness, overhangs (areas that would need supports) and watertightness (holes or inside-out faces a slicer can’t fill) before you export STL or 3MF.
Drop the file on the build plate, check its size, and export an STL for your slicer (Bambu Studio, PrusaSlicer, Cura or OrcaSlicer).
It opens on your device, it is saved to your workspace as you work, and it exports back out in the format your slicer wants.
Your browser reads and renders the model itself, so it appears as soon as you drop it in — you are never queued behind anyone else’s upload, and the file does not travel anywhere before you can see it.
Most online viewers forget your file the moment you close the tab. OwlCAD keeps the model in your own workspace and syncs it as you work, so it is still there when you come back to this browser. Create a free account and it follows you to any device, and your projects dashboard lets you delete anything you no longer want.
When you are done, export STL, 3MF, OBJ, GLB or STEP — the format your slicer or your colleague actually needs, not a project file that only opens here.
STL stores flat triangles, so curved faces become fine facets. That is true of every STEP to STL conversion, and at printing resolution it is not visible. Keep the STEP for CAD work and use the STL or 3MF for printing.
Yes. STEP files record their units, so the part arrives at its true size in millimetres, and there is no unit to guess as there is with a plain STL.
Yes. Resize it, combine and cut it with other parts (union, subtract, intersect), add a base, then run the print check and export STL or 3MF.
Yes. Importing, editing and exporting in OwlCAD is free, and you can start without an account. AI generation is the optional Pro upgrade.