I got this working with ONNX (thanks, Claude Opus 4.8) and now I have an interactive demo of the model running entirely in the browser here (~1.3GB download): https://simonw.github.io/moebius-web/ - code here: https://github.com/simonw/moebius-web

(Claude Code transcript: https://gisthost.github.io/?58039ba5c1ca3ed177e8659168996ee4)

Wrote this up in more detail on my blog: https://simonwillison.net/2026/Jun/22/porting-moebius/

Awesome, I wanted to do the exact same thing (used gpt 5.5 + code) but it didn't get the model to work in onnx...

well done!

unet weights are in fp32. did you by any chance try something lower, fp16?

The model considered it.

There are 25 or so mentions of fp16 and fp32 weights across the 7500+ words of Markdown text it generated. So the next question might be: Did it make the right calls?

https://github.com/simonw/moebius-web/blob/main/notes.md

https://github.com/simonw/moebius-web/blob/main/plan.md

https://github.com/simonw/moebius-web/blob/main/research.md

https://github.com/simonw/moebius-web/blob/main/understandin...