Free 3D converter / STEP to STL
Convert STEP to STL, free and online
Turn a .step or .stp file into a .stl file. It runs in your browser: no sign-up and nothing to install, and most files never leave your computer.
Drop your STEP file here
or choose a file
Free · No sign-up · Converted in your browser · Files up to 1 GB
What you get: STEP describes exact curved surfaces; STL needs triangles, so the surfaces are turned into triangles, accurate to 0.1% of the part's size (0.1 mm on a 100 mm part). Assemblies keep their parts and colours where the target format can hold them.
How to convert STEP to STL
- 1Drop your .step or .stp file
On the converter above, or click to choose it. - 2Click Convert to STL
The .stl file downloads straight away.
STEP vs STL
STEP: STEP (ISO 10303) is the CAD exchange format: SolidWorks, Fusion 360, Inventor, CATIA, Creo, Onshape and FreeCAD all read and write it. It describes exact surfaces, not triangles.
STL: STL describes a shape as triangles only: no units, no colours, no curves. It's what 3D printers, slicers and scanners use.
Other conversions
All conversions →Is the STEP to STL converter free?
Yes, with no sign-up and no limit on the number of files. A free account is only needed if you want to send the model to someone for feedback.
Is my file uploaded?
Most files are read and converted right in your browser and never leave your computer. Very large CAD and mesh files are converted on our server instead, then deleted straight after the converted model is sent back to your browser.
What's the biggest STEP I can convert?
Up to 1 GB. Big files take longer, and very large CAD files go through our server, as above.
What units is the STL in?
Millimetres, which is what CAD programs and slicers expect.
Does it keep colours?
No. STL has no colours or materials, only the shape. Convert to GLB to keep them.
Converting it to send to a client or supplier?
Send them a link instead. They open the model in any browser, with no account and no CAD program, and click the spot they want changed.