FreeCAD Runs in Your Browser: A Massive CAD Port to WebAssembly
FreeCAD in the Browser
I successfully ported FreeCAD, a massive parametric 3D CAD application with over 1.5 million lines of code, to run entirely in a browser tab. Using Qt for WebAssembly and JSPI, this feat took just four days with the help of Fable, an AI agent. The result is a fully functional, scriptable CAD kernel and GUI that runs on modern Chromium browsers, proving that even complex desktop applications can scale to the web.
It is roughly an order of magnitude larger than the other two — about 1.5 million lines of C++ and 700 thousand of Python — and it now runs in a browser tab.
- ebspelman
The launch graphic says "Ported end-to-end by Fable, an AI agent" and it definitely feels that way. Buggy, glitchy, needs some love and human eyes before it's really usable.
- dang
Recent and related:
LibreCAD in the Browser - https://news.ycombinator.com/item?id=48755075 - July 2026 (17 comments)
- techbro92
Why would I want to run this in the browser vs locally?
- s1mon
Onshape is free in the browser as long as you are not doing commercial work. It’s a professional system from the founders of Solidworks that competes with all the top CAD tools.
- dd8601fn
Sounds cool. Doesn't work.