I no longer have any inside knowledge, but from my time on this team they were very quick about getting the latest small (Google) models into Chrome. I expect that if Gemma 4 (or its equivalent Gemini Nano) isn't already in Chrome, then it will be soon.
Note that the article here was last updated 2025-09-21, and as of that time it was already on Gemini Nano 3.
Note that the article here was last updated 2025-09-21, and as of that time it was already on Gemini Nano 3.