Drop a .step or .stp file below to open real CAD geometry without a CAD license. The viewer runs OpenCascade compiled to WebAssembly directly in your browser, tessellates the B-rep solids locally and renders them with three.js — your design never leaves your machine.
STEP files are tessellated by occt-import-js (OpenCascade WASM) — genuine B-rep geometry, not an approximate guess.
Engineering data is sensitive. The WASM kernel runs locally, so your supplier's or client's design is never uploaded.
Part colors stored in the STEP file carry through to the rendered model.
Open vendor files without SolidWorks, Fusion or FreeCAD — useful for quick checks on any machine.
Drag a .step or .stp into the drop zone. The CAD kernel loads on demand (a few MB of WASM, cached afterwards).
The solids are converted to display meshes locally — complex assemblies can take a few seconds.
Orbit, zoom and check the geometry, features and part colors before importing into your CAD tool.
STEP (ISO 10303, extensions .step/.stp) is the neutral exchange format for mechanical CAD. Unlike mesh formats such as STL, it stores exact boundary-representation solids — analytic surfaces, edges and topology — which is why manufacturers, suppliers and engineers exchange parts as STEP. Opening one normally requires CAD software; this tool does it in the browser instead.
The viewer loads OpenCascade Technology compiled to WebAssembly (occt-import-js). Your file is read into memory, the kernel tessellates each solid into triangles at display quality, and three.js renders the result. Because tessellation happens on your machine, nothing is uploaded — and you can inspect files from vendors without a seat of commercial CAD.
Yes. The browser downloads a WebAssembly build of the OpenCascade kernel and does the conversion locally — no CAD license or install involved.
No. The STEP file is processed entirely in your browser's memory. That makes the tool safe for NDA'd or pre-release designs.
Yes — they are the same format with two common extensions, and the viewer accepts both.
Typical parts and mid-size assemblies open comfortably. Very large assemblies are limited by browser memory and may take longer to tessellate.
This free tool focuses on visual inspection. For dimensioned review you'll still want your CAD package — but for "is this the right part, does it look correct", the browser is enough.
Type a prompt, get a textured 3D model in about a minute — then download it as GLB, STL, OBJ, FBX or USDZ.
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