Step 1
Choose a STEP file
Select a .step or .stp model up to 100 MB. The file remains on your device.
Free · Private · Browser-based
STEP to STL Converter Online
Turn precise STEP CAD solids and assemblies into slicer-ready STL meshes. Conversion runs locally in your browser, with adjustable tessellation quality for curved surfaces.
Drop STEP or STP file here
or browse your computer
Max 100 MB · processed locally
Your CAD file stays on this device. Only the converter engine is downloaded; model data is never uploaded.
How to convert STEP to STL
Step 2
Select mesh quality
Balanced works for most parts. Fine adds more triangles around curves; Draft creates a smaller STL.
Step 3
Download STL output
Download one binary STL, or a ZIP bundle when the CAD file contains multiple parts.
STEP and STL are different geometry types
STEP is the long-form extension for ISO 10303 CAD exchange files. It stores exact curves, surfaces, solids, colors, and assembly structure. STL stores only triangles, so conversion tessellates each CAD surface into a printable mesh.
| Property | STEP | STL |
|---|---|---|
| Geometry | Exact CAD surfaces | Triangle mesh |
| Units | Defined in the file | Not explicitly stored |
| Best for | CAD exchange and editing | Slicing and 3D printing |
STEP to STL FAQ
Is this STEP to STL converter really local?
Yes. The OpenCascade CAD engine runs in a browser worker. Your STEP model is not uploaded to a conversion server.
Does STEP to STL lose quality?
STL approximates exact CAD curves with triangles. Select Fine for smoother curved surfaces, then verify dimensions before printing.
Can it convert STEP assemblies?
Yes. Imported parts are exported as individual STL files and packaged into a ZIP when more than one part is found.
Are STEP and STP different formats?
No. STEP and STP use the same ISO 10303 file structure. Only the filename extension differs.
Same CAD format, different extension
Use the matching page if your filename uses the other common extension.