Chromium mostly does not support this, because it doesn't have the binary blob required to run the inference. However, it does still download the model weights and expose the LanguageModel API, because that part is hooked up.

https://adsm.dev/posts/prompt-api/#which-browsers-support-th...

Packagers might eventually disable that but I tested this behaviour in chromium 148 a few hours ago, and it would download the weights but has trouble running them.