How it works
This viewer runs entirely in your web browser. No files are ever uploaded to a server.
STL files are loaded directly via Three.js's built-in STLLoader, which parses both ASCII and binary STL formats natively in JavaScript.
STEP and STP files are parsed in-browser via occt-import-js, a WebAssembly build of OpenCascade Technology (OCCT) — the same geometry kernel used in professional CAD software. The WASM module runs entirely on your device; your model geometry never leaves the browser.
Once loaded, models are rendered using Three.js's WebGL renderer with a physically-based material (PBR) supporting metalness and roughness, a dual-light rig, and an orbit camera with damping. Measurement is done by raycasting into the scene geometry and operating directly on buffer attribute data — no server round-trips involved.
Privacy
No accounts. No tracking pixels on your model files. No uploads.
Open your browser's developer tools and check the Network tab while loading a model — you will see zero requests carrying your file data. The only external requests are the initial page load (HTML, CSS, JS, Three.js CDN, occt-import-js CDN) and the Cloudflare analytics beacon (page view count only, no file data).
Your 3D models are processed in memory by your own browser and discarded when you close the tab.
Supported formats
- STL — ASCII: plain-text triangle soup, parsed by Three.js STLLoader
- STL — Binary: compact binary format, also parsed by Three.js STLLoader
- STEP / STP — AP203: configuration-controlled design, via OpenCascade WASM
- STEP / STP — AP214: automotive/aerospace design, via OpenCascade WASM
STEP support depends on the occt-import-js library (v0.0.22). Very large or highly complex STEP assemblies may take several seconds to tessellate as WASM runs single-threaded.