Google has confirmed that Chrome can place a multi-gigabyte Gemini Nano model on supported desktop machines in the background, after users and researchers drew attention to a large weights.bin file appearing inside Chrome profile folders.

What Google confirmed

In Chrome's developer documentation, Google says Gemini Nano downloads are handled automatically when built-in AI features need the model, and that some checks can happen shortly after startup. The company also says the model may be removed automatically if a device runs low on resources.

Google's Help Center now has a user-facing page explaining that Chrome may download on-device generative AI models in the background so features stay ready for use. That page says users can turn On-device AI on or off under Settings > System, and that disabling it removes access to features that depend on the local model.

Why the issue surfaced now

The current backlash started after privacy researcher Alexander Hanff documented a roughly 4 GB OptGuideOnDeviceModel directory appearing on a fresh macOS audit profile, then described similar delete-and-redownload behavior reported by other users. In a statement to Android Authority, Google said the file powers local AI features such as scam detection and developer APIs, and added that an easier settings toggle to turn it off has been rolling out since February.

The conservative takeaway is narrower than the online outrage: Chrome is not secretly uploading user prompts through this file, but it is downloading a large local model on eligible desktops, and Google is only now making the opt-out path more visible.