Stop Chrome from silently downloading Gemini Nano AI model on Windows 11

• Google Chrome automatically downloads the Gemini Nano model when AI features are enabled and used.
• The model is stored as a 4GB weights.bin file in the “OptGuideOnDeviceModel” folder under %LOCALAPPDATA%.
• Some users report that the download happens without a clear opt-in prompt and significantly increases disk usage.
• Deleting or renaming the file is temporary because Chrome automatically restores it.
• A Registry tweak change can fully prevent Chrome from downloading or restoring the local AI model.

On Windows 11 and other supported platforms, Google Chrome can download local AI models automatically without presenting a clear opt-in prompt. If you are trying to keep tighter control over storage usage and background components, this guide explains how to stop that behavior.

By default, Chrome pulls down the Gemini Nano model when you interact with AI-powered features such as “Help me write.” The model is stored as a file called weights.bin, which is roughly 4GB in size and located in the %LOCALAPPDATA%\Google\Chrome\User Data\OptGuideOnDeviceModel folder. For many users, the discovery happens only after noticing a sudden spike in disk usage.

Related

How to permanently disable all Google Chrome AI features via Registry on Windows 11 (it works)

Although the topic recently resurfaced on social platforms, this behavior is not new. Discussions about the OptGuideOnDeviceModel folder and the large weights.bin file appeared on community forums more than a year ago, with users questioning why Chrome’s disk footprint had grown so dramatically. Those with smaller SSDs often point out that a single 4GB model can feel excessive compared to the browser’s original installation size.

The core frustration isn’t only the file’s size but how it arrives. Users repeatedly report that the model downloads silently, without a prominent consent dialog, and that it can appear even if they rarely use AI features. A lot of users see this as a forced opt-in rather than a clearly communicated feature activation.

Attempts to remove the file usually prove temporary. Deleting weights.bin, renaming it, or removing the entire “OptGuideOnDeviceModel” folder typically results in Chrome restoring the contents automatically. Even replacing the file with a read-only placeholder may only work until the next browser update. This automatic regeneration has become one of the most cited complaints.

The good news is that the behavior can be fully disabled through a policy change in the Registry, preventing Chrome from downloading the on-device AI model in the first place.

In this guide, I’ll outline the steps to delete the weights.bin (Gemini Nano) file from your computer and prevent Chrome from redownloading it in the future.

Prevent Chrome from downloading AI models on Windows 11

To prevent Google Chrome from downloading AI models like Geminin Nano on Windows 11 using the Registry, follow these steps:

1. Open Start on Windows 11.

2. Search for regedit and click the top result to open the Registry.

3. Open the following path:

   HKEY_LOCAL_MACHINE\SOFTWARE\Policies

4. Right-click the Policies key, select New, and choose Key.

   

5. Confirm the Google name and press Enter.

6. Right-click the Google key, select New, and choose Key.

7. Confirm the Chrome name and press Enter.

8. Right-click the Chrome (folder) key, select the New submenu, and choose the “DWORD (32-bit) Value” option.

9. Confirm the GenAILocalFoundationalModelSettings name and press Enter.

10. Right-click the newly created key and select Modify.

11. Set the value to 1 to prevent Chrome from downloading and using locally available AI models on your device.

    

12. Click the OK button.

13. Restart your computer.

Once you complete the steps, Google Chrome will no longer download AI models (such as Gemini Nano) on your computer, and any existing model (if already downloaded) will be deleted.

You may come across guides recommending that you disable the feature through the chrome://flags page and then manually delete the weights.bin file. However, that approach is not the most reliable or permanent solution.