STL Converter/convert/step-to-stl
Browser converter·no upload

STEP to STL, in your browser.

Drop a .step CAD assembly — a real OpenCascade kernel meshes it in your browser via WebAssembly.

viewer● live
drop a file to preview
Drop your .step / .stp file
or click to browse · local only
Output format

100% local · file never leaves your browser

// about

STEPSTL: what changes.

STEP (ISO 10303) is the parametric CAD interchange format — used by Fusion 360, SolidWorks, Onshape, FreeCAD. It carries true B-Rep geometry: surfaces, edges, assemblies.

STL is a mesh of triangles. We tessellate the B-Rep with the OpenCascade kernel (~7 MB WASM, loaded once) at a printer-friendly tolerance. The first conversion takes a beat as the kernel boots; subsequent ones are instant.

Fully private

The file is parsed in WebAssembly + WebGL on your device. Nothing leaves.

Instant

No queue, no upload. Most files convert in well under a second.

Inspect before download

Orbit, pan and zoom the result in real time before you commit.

// faq

Frequently asked

Why is the first load slow?

OpenCascade WASM is ~7 MB. It's cached after the first download — subsequent conversions are fast.

Are assemblies preserved?

All parts are tessellated and welded into a single STL. Use your slicer if you need per-part placement.

What's the tessellation quality?

Default tolerance is tuned for FDM printing (~0.1 mm chord error). Curves look smooth at typical print scales.