STEP to STL Converter
Convert STEP to STL free in your browser. Files never leave your device.
Drop files anywhere on this pageTap to choose a file
Mix any types. We detect each one and pick its best format.Photos, Files or iCloud • up to 100 MB
Up to 100 MB per file • Multiple files at once • Ctrl+V works too
How to convert STEP to STL
Add your STEP (.step) file
Drag and drop your .step file into the converter box above or click Choose files. You can also paste screenshots or clipboard data with Ctrl+V.
Convert to STL (.stl)
Our in-browser engine processes your .step file directly in memory. No files are uploaded to any server, guaranteeing 100% private conversion.
Download your fresh .stl
Click Download to save your newly converted .stl file to your device. There are zero watermarks, zero size traps, and no waiting room.
What are STEP and STL files?
What is a STEP file?
.stepISO standard industrial 3D CAD solid model. STEP files are widely utilized across desktop applications and digital workflows, but may require conversion when sharing with recipients who lack native viewing software.
What is a STL file?
.stlStandard Stereolithography 3D triangular mesh format. Converting to STL format ensures universal compatibility across modern browsers, mobile devices, and third-party software suites.
STEP to STL conversion settings explained
When converting STEP to STL, precision matters for slicing and 3D printing:
- Linear Deflection (Chordal Deviation): Controls how closely triangular facets follow curved surfaces (0.01 mm for precision parts, 0.1 mm for rapid prototyping).
- Angular Deflection: Determines the angle between adjacent facet normals along curved fillets, ensuring smooth circular silhouettes without polygon stepping.
- Manifold & Watertight Validation: Verifies that meshes have no open edges or non-manifold junctions before export into slicing software like Cura or PrusaSlicer.
Frequently asked questions about STEP to STL
Is the converted STL file ready for 3D printing?
Yes. The generated STL is a watertight, manifold triangular mesh that opens cleanly in all 3D slicers including Cura, PrusaSlicer, and Bambu Studio.
How does mesh resolution affect 3D printing?
A finer chordal tolerance produces smoother curves on circular features at the cost of more triangles and larger file sizes.
Does this tool support AP203, AP214, and AP242 STEP protocols?
Yes. Our OpenCASCADE CAD engine parses standard ISO-10303-21 STEP protocols with support for multi-body solid models.
Do proprietary CAD models leave my computer?
No. OpenCASCADE runs entirely in client-side WebAssembly. Your engineering files remain 100% confidential.