You didn’t click yes.
You weren’t asked.
Yet if you are reading this on a desktop running Chrome, there is a good chance a 4GB file named Gemini Nano is squatting in your storage right now.
It happened quietly. Between late April and May 2026, Google pushed this update to eligible machines. No pop-up. No consent form. Just code executing in the background while you tried to work or watch videos.
Security researcher Alexander Hanff — better known online as That Privacy Guy — pointed this out. He is Swedish, a computer scientist, and apparently the guy who cares when we stop looking at the small print.
The model itself runs locally. Not in the cloud. This is the difference between Gemini Nano and that little pill-shaped icon in your address bar that calls AI Mode. If you type something into that bar, the data goes to Google’s servers. Gemini Nano? That stays put. On your drive. Chewing through cycles to summarize text, analyze screenshots, or maybe flag a scam call.
It is efficient. It is also presumptuous.
Hanff says he does not know exactly how many machines received the drop, only that Chrome decided your hardware was ready for it without bothering to ask. If your processor slows down or your storage fills up, the model supposedly vanishes. A spokesperson for Google told CNET the company rolled out a switch to kill it off back in February.
“In February, we began rolling out the capability for users to easily turn off… Once disabled, the model will not update.”
That implies a choice exists. The problem is, most of us do not see it unless we actively look for a file we were never told to find.
How to check (and scrub it)
Want it gone? You have to hunt.
On macOS, the process feels like a scavenger hunt designed to make you give up. Open Finder. Click Go in the menu bar. Hold down Option so you see Library.
Drill down to: Application Support > Google > Chrome > Default.
Look for a folder named OptGuideOnDeviceModel.
Inside? Check for weights.bin.
If it is there, the beast has moved in. To make it leave for good, go into Chrome Settings. Click System. Flip the toggle for On-device AI off.
Windows is a bit easier, assuming you know how to use File Explorer.
Open a Run window (Windows Key + R) and paste this in:
%LOCALAPPDATA%\Google\Chrome User Data OptGuideOnDeviceModel
Or browse to:
C: Users [YourUsername] AppData Local Google Chrome User Data
Same folder. Same weights.bin file.
Removing it on Windows takes more muscle.
- Turn off
On-device AIin Settings > System. - Type
chrome://flagsin the address bar. Search for “optimization guide”. SetEnables optimization guide on-deviceto Disabled. - Close Chrome completely. Not just the tab. Exit the app.
- Go back to that folder path. Delete the
OptGuideOnDeviceModeldirectory.
Do you feel secure now? Or just lighter on gigabytes?
The cost of free
Why do this? Why hide a file?
Hanff suggests the answer is money. Simple server costs. Running AI on your CPU means Google saves on theirs. They move the processing load from their data centers to your laptop battery. It is clever business logic.
It is also arguably illegal in parts of the world.
The EU cares about lawfulness and transparency. By installing a 4GB model without a clear prompt, Google might have violated the GDPR. Hanff thinks the lack of a consent screen was a deliberate feature. Asking for permission is friction. Friction kills conversion rates.
“Google has given us every reason to doubt their handling of personal data.”
He argues the move fits a twenty-year pattern of grabbing what it can while users stare at something else. Maybe Google figures we are too tired to hunt for files in hidden application support folders.
Or maybe they just figured we wouldn’t notice the weight gain in our storage drives.
Until regulators decide to make a fuss, or until we all collectively delete Chrome out of spite, the files remain. They sit there, waiting to summarize an email or analyze a pixel array, powered by hardware they do not own but decided was ready to share.
