Winaero published a blog post yesterday (February 27) stating that Google Chrome browser downloads approximately 4GB of Gemini Nano AI model files to the local system by default without explicit user authorization.
X platform user @zephyrianna was the first to discover this anomaly. She noticed unusual space usage on her C drive and eventually identified a massive 4GB file named “weights.bin,” primarily hidden in the following paths on her C drive:
C : \Users\<username > \AppData\Local\Google\Chrome\User Data \OptGuideOnDeviceModel
Further analysis by the netizen revealed that this is the Gemini Nano model deployed by Google to run its built-in AI API on PCs. The netizen subsequently tested this and found that the integration is currently limited to the Chrome browser; Chromium-based browsers such as Edge have not yet been found to have incorporated the model.
It was revealed that a user had reported this issue as early as November 2025:
Here are some ways to prevent Chrome from downloading AI models:
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Enter chrome://flags/ in your browser’s address bar and press Enter.
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Locate the “Enables Optimization Guide On Device” experimental flag and select “Disable”.
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Locate the experimental flag for the Prompt API and select Disable.
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After disabling the experimental flags mentioned above, delete the approximately 4 GB model file weights.bin located in the aforementioned path.
Improper changes can severely disrupt the normal operation of the application. For safety, users can try renaming the file and restarting Chrome to test before proceeding with the deletion.
