Why Chrome may have quietly downloaded a 4GB file to your PC - and how to get rid of it

Source: ZDNet

ZDNET’s key takeaways

• Google is downloading a 4 GB file to the PCs of many Chrome users.
• The file is harmless and is used for the Gemini Nano on‑device LLM.
• You’ll see it if you’ve opted into the on‑device AI setting in Chrome.

Google is silently saving a Chrome‑related file to many computers. The file, named weights.bin, is 4 GB and is part of the Gemini Nano on‑device AI model that Google ships with Chrome.

Also: I let Chrome’s AI agent shop, research, and email for me – here’s how it went

In a new blog post, computer scientist Alexander Hanff (the “Privacy Guy”) explains that the file is downloaded deep within the Chrome user‑data folder.

If you delete the file, it comes back

The file isn’t risky, but it is downloaded without explicit user consent, and it returns after deletion. That behavior is typical of software updates, but the size (4 GB) raises concerns for users with limited disk space.

Traditionally, AI models like Gemini run in the cloud, requiring an internet connection and exposing data in transit. Locally stored LLMs—such as Gemini Nano—run on the device, offering faster responses, offline capability, and better privacy. Gemini Nano is already in use on Google Pixel phones.

The large size is due to the weights file, which stores the numerical parameters the model uses to make predictions. For example, when you type “Why did my new phone cost me an arm and a…”, the model’s weights help it predict the next word (“leg”).

Also: This powerful Gemini setting made my AI results way more personal and accurate

How to check if the file is on your PC

1. Open Chrome → Settings → System.
2. If On‑device AI is enabled, the file is likely present or will be downloaded soon.

To verify, locate the file in your user folder. The path varies by OS. On Windows 11, the file was found at:

C:\Users\<username>\AppData\Local\Google\Chrome\User Data\OptGuideOnDeviceModel\2025.8.8.1141\weights.bin

The file size reported was ~4 GB.

Removing the file permanently

1. Delete weights.bin from the folder above.
2. Return to Chrome Settings → System and turn Off the On‑device AI switch.

As long as you have sufficient disk space, the file poses little risk. If you need the space, disabling the feature prevents the file from being re‑downloaded.