Preview your .stl here, then reverse-engineer it in a CAD tool — we'll explain why.
Converting a triangle mesh to a parametric STEP B-Rep needs a CAD kernel (Fusion 360, FreeCAD, Rhino). The result is rarely clean. Preview your mesh here, then reverse-engineer it in your CAD tool.
100% local · file never leaves your browser
STL is a soup of triangles. STEP is a parametric B-Rep — analytic surfaces, edges, faces, assemblies. There's no clean algorithm that infers surfaces from triangles; the result is always lossy and rarely usable for downstream CAD edits.
Use FreeCAD (free) or Fusion 360 (free for hobbyists) with their mesh-to-BRep workflows. For organic shapes, Rhino's QuadRemesh + SubD is the cleanest pipeline.
The file is parsed in WebAssembly + WebGL on your device. Nothing leaves.
No queue, no upload. Most files convert in well under a second.
Orbit, pan and zoom the result in real time before you commit.
Mesh-to-BRep needs a CAD kernel (OpenCascade, Parasolid) and surface fitting heuristics. A browser tool can't produce CAD-quality output.
Fusion 360 imports STL natively as a mesh body. Convert to BRep inside Fusion if needed.
FreeCAD: Mesh workbench → Convert to solid → Part workbench → Export STEP. Imperfect but usable.