[827a]

The more I think about it, the more I think I align with Google's API design on this one.

The tight coupling between prompts and models is a real concern. I deal with that every day. However: if your solution to that is to support an API that enables tighter coupling between the model the user's browser has and the prompt that gets evaluated, you will inevitably and quickly enter the domain of "You need to use Chrome to use this site (because our prompts were only tested on Gemini)" or even worse "We don't recognize the AI model you're using (because the website was written in 2026 and the current year is 2030 and they never updated it)".

This is related to the terms of use concerns the Mozilla engineer has later; real concerns. But, if we want browsers to exist that don't require users to opt-in to the terms of use of a specific AI model (e.g. using a nice open source model), its beneficial to these browsers that they can't fingerprint for the Big Models.

Of course many sites will just do an isChrome()-like call anyway. Nothing to be done about that. But yeah I am generally non-supportive of changes that introduce more ways to fingerprint browsers. The upside of keeping the model anonymous outweighs the slight downside of (rarely) encountering weird prompt evaluation output because of a small difference in behavior between Gemini and, idk, Qwen.