I saw Microsoft is deprecating 3D Viewer and removing it from Store in July. I always had trouble checking STEP files quickly - you have to open a slicer or full CAD software just to look at a part. So I built a viewer.

https://viewer.3dlab.id - drag and drop a file, it renders in browser. No signup, no install.

Formats: STL, STEP/STP, OBJ, 3MF, GLB

STEP parsing runs via OpenCascade compiled to WebAssembly (occt-import-js), all client-side in a Web Worker so it doesn't block the UI.

Stack: React, TypeScript, Three.js, Vite. Backend for sharing is Cloudflare Pages Functions + D1 + R2. There's also a Windows desktop version built with Tauri, but not released yet.

Other features: - multiple files in tabs - wireframe mode, ortho/perspective toggle - share models via link (expires in 7 days) - dark/light theme

The sharing is useful when you need to send a model to someone who doesn't have CAD software - they just open the link and see it, no account needed.

Still WIP, feedback welcome. Source code is on GitHub: https://github.com/Goodsmileduck/3d-lab-viewer