google chrome has been downloading silently 4GB of Gemini Nano AI model weights to users’ devices without their consent, and automatically redownloads files if they are deleted. This behavior has been confirmed on Windows 11, Apple Silicon, and Ubuntu systems, and user reports indicate that it has been happening for about a year.
The files are stored in a folder named OptGuideOnDeviceModel. On Windows 11, the path is %LOCALAPPDATA%\Google\Chrome\User Data\OptGuideOnDeviceModel.
What is the Gemini Nano 4GB Chrome download used for?
The 4GB folder is not used for Chrome’s core AI features. The AI mode that appears in the address bar and Google Search runs on Google servers, not locally stored weights. The downloaded model is only used for typing assistance and some other functions that can be accessed through various menus in the browser.
Users who have not enabled or searched for those features may have the model stored on their device without realizing that it fulfills any of the functions they use.
How to check and remove the AI model from Chrome
Deleting the OptGuideOnDeviceModel folder does not prevent Chrome from downloading it again. The most reliable way to remove it is to uninstall Chrome completely.
If you want to disable downloading without removing Chrome, you can try the following:
- Type chrome://flags in the address bar.
- Search for “Enable optimization guide on Android device”.
- Set the dropdown menu to Off.
This flag also shows if a device is eligible for the feature. Older hardware may not qualify and the download appears to be limited to newer machines.
Why Chrome’s AI Silent Download Raises Privacy Concerns
Alexander Hanff, a computer scientist and lawyer who verified the behavior through macOS kernel file system logs, formally accused Google of violating European privacy laws by forcing users to download large amounts of data without their knowledge or consent.
Hanff estimates that distributing 4 GB to hundreds of millions or even billions of Chrome users could be equivalent to several exabytes of data transfer and generate between 6,000 and 60,000 metric tons of CO2 emissions.
Google has not publicly responded to these claims or explained why users are not notified before downloads begin.
