July 10, 2026

CAD Fight Club opens in a tab

FreeCAD in the Browser

A giant 3D design app lands in your browser — and the comments are already fighting

TLDR: FreeCAD, a huge free 3D design app, now runs in a web browser — a surprising step that could make powerful desktop software easier to access. But the comments quickly split between impressed onlookers, rival-tool fans, and skeptics calling it buggy or pointless compared with installing it normally.

A massive free 3D design program called FreeCAD has been squeezed into a browser tab, and honestly, the real spectacle is the peanut gallery losing its mind. The creator says this huge app — normally something you install on a computer — was brought to the web in about four days, with an AI helper doing almost all the heavy lifting. That alone was enough to set off the comment section sirens: some people were amazed, some were skeptical, and some went straight for the jugular.

The biggest split was simple: “Cool trick, but why would I want this?” One commenter basically asked why anyone would use this in a browser instead of just running it normally on their machine. Another immediately brought up Onshape, a browser-based design tool, as if to say, “Cute demo, but this market already has a favorite.” Then came the brutally short review every experimental web app fears: “Sounds cool. Doesn’t work.” Ouch.

And yes, there was prime AI drama. One commenter pointed to the launch screen bragging that it was “ported end-to-end by Fable, an AI agent,” then twisted the knife: it “definitely feels that way” — buggy, glitchy, and in need of human cleanup. That’s the mood in one sentence: part miracle, part mess. Still, even the doubters seemed fascinated, and one of the funniest reactions cut through all the technical flexing with the most internet question possible: “Amazing. How much did it cost?”

Key Points

  • The article reports that FreeCAD has been compiled to WebAssembly and can run in a browser tab, extending a pattern previously used for LibreCAD and OpenSCAD.
  • The current browser build took about four days to reach its stated state, and the post says all 48 prompts and full session transcripts were published for verification.
  • The application has a first-load size of about 96 MB compressed and requires recent Chromium-based browsers because it depends on WebAssembly JSPI, which Firefox and Safari do not yet support.
  • The browser port statically links a large native stack including OpenCASCADE, Coin3D, CPython 3.14, PySide6, shiboken6, VTK 9.3, and SMESH into one 196 MB WebAssembly module with Qt 6.11.
  • A key technical requirement was preserving `QDialog::exec()` semantics across 185 C++ and 156 Python modal dialog call sites, leading to a custom Qt 6.11.1 wasm build with JSPI and native wasm exceptions on Emscripten 4.0.12.

Hottest takes

"Why would I want to run this in the browser vs locally?" — techbro92
"Sounds cool. Doesn't work." — dd8601fn
"it definitely feels that way" — ebspelman
Made with <3 by @siedrix and @shesho from CDMX. Powered by Forge&Hive.