The MLC team got that working back in March: https://github.com/mlc-ai/web-stable-diffusion
Even more impressively, they followed up with support for several Large Language Models: https://webllm.mlc.ai/
Even more impressively, they followed up with support for several Large Language Models: https://webllm.mlc.ai/
I've since moved away from ONNX and to a more GGML style.
Being bound to ONNX means moving at a slower velocity - the field moves so fast that you need complete control.