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STEP to STL Converter

Convert STEP / STP 3D CAD files into 3D printable STL mesh format in-browser using WebAssembly. Customize tessellation, preview in interactive 3D, and download binary STL.

Interactive Online Utility

STEP to STL Converter runs 100% locally in your browser sandbox with zero network roundtrips. Load or paste your code directly into the workspace above to format, parse, validate, or generate your output instantly.

PRO TIP Chordal Tolerance & Angular Deflection

STEP is a continuous mathematical boundary representation (B-Rep), while STL approximates curved surfaces with flat triangles. Tighter deflection values yield smoother curved surfaces on 3D prints at the cost of higher polygon counts.

Technical Guide & Overview

STEP (ISO 10303-21) is the international standard for the computer-interpretable representation and exchange of product manufacturing data. Unlike polygon meshes (STL), STEP uses precise mathematical Boundary Representation (B-Rep).

How It Works Under the Hood

Otuls runs the OpenCASCADE Technology (OCCT) CAD modeling kernel compiled to WebAssembly (Wasm) inside your browser. It parses STEP curves, analytical surfaces, and topological solids, performing Delaunay boundary triangulation to export clean, manifold STL meshes at user-configured deflection tolerances.

Authoritative Specifications & Primary Standards

Official specifications, RFCs, and authoritative open-source repositories for STEP to STL Converter:

ISO Standard

The international ISO standard for 3D CAD Boundary Representation (B-Rep) geometry.

GitHub Repository

Authoritative open-source C++ solid modeling and CAD triangulation kernel.

CLI Equivalents & Terminal Automation

Convert STEP to STL via FreeCAD CLI:
freecadcmd -c "import Part, Mesh; shape = Part.read('part.step'); Mesh.export([shape], 'part.stl')"
Batch convert CAD solid models to polygon meshes in terminal.

Zero-Knowledge Client-Side Sandboxing

Proprietary CAD files and industrial IP are converted client-side via WebAssembly. No aerospace, defense, or automotive geometry leaves your workstation.