For the third time, Google sneaks something onto your PC without asking

If you use Chrome, there are 4GB of an AI model sitting on your machine that you never asked for. And it is not the first time Google does this, it is the third. Privacy researcher Alexander Hanff published the report on May 4, 2026. The file is called weights.bin, lives in OptGuideOnDeviceModel inside the Chrome user data directory, and it is the Gemini Nano model. No prompt, no checkbox. Find it and delete it, and Chrome re-downloads it on the next restart.

The first reaction here was déjà vu, not surprise. In December 2020, Loren Brichter (@lorenb on X, the guy behind "pull to refresh" and Tweetie, the client Twitter bought in 2010 to become its official iPhone app) published chromeisbad.com, a one-page site explaining how Keystone, Google Chrome's updater on Mac, kept running in the background, dragging the system down even when Chrome was closed. His complaint came eleven years after Wired published "Google Software Update Tool is evil" about the same Keystone, when it showed up bundled with Google Earth, gathering hardware data and downloading things in the background without warning. Brichter's prescription was a manual uninstall guide for Chrome and Keystone, plus a list of replacements: Safari, Brave, Vivaldi, Opera.

What Hanff found

His discovery is more detailed than Brichter's was in 2020. Hanff cross-referenced macOS filesystem logs (.fseventsd), Chrome's Local State, feature flags, and GoogleUpdater logs to build a four-way evidence chain. On his test profile, weights.bin appeared on April 24, 2026 at 16:38:54 and took 14 minutes and 28 seconds to finish downloading. Silently. Each Chrome profile runs the process again.

The affected version is Chrome 147 onward. The model powers features like "Help me write" (text composition), local scam detection, and APIs that sites can call (Summarizer API, Translator API, Prompt API).

The frustrating part

That bright "AI Mode" pill that showed up in Chrome's omnibox, the visible AI feature of the browser, does not use the local model. Queries typed there are sent to Google's cloud. So the user pays 4GB of download and 4GB of disk for a model that does not run when they click the most prominent AI button on the browser. The cost lives with the user, the use lives with Google.

At scale

Hanff did the math: 0.24 kWh per device for the download and install, 0.06 kg of CO2e per device. At 1 billion installs, that is 240 GWh and 60,000 tonnes of CO2e, equivalent to the annual emissions of about 13,000 European cars. And with the European Union watching closely on GDPR, the ePrivacy Directive (Article 5(3) prohibits storing data on a user's device without prior consent), and the Corporate Sustainability Reporting Directive, the chance of this turning into a legal case is high.

How to remove it

Google added an opt-out in February 2026:

Chrome Settings > System > "Turn On-device AI on or off", if the option is showing up for you yet.
Alternative path: type chrome://flags in the address bar, search for "optimization guide on device", and set it to "Disabled". Restart Chrome.

Note that deleting weights.bin by hand is not enough. Without disabling the flag, Chrome downloads it again.

What I do in my daily setup

I have not been using Chrome as my main browser for a long time. I wrote last week about link routing, and in the setup I describe there the browsers that open each link are Chromium-based or Firefox-based (Brave, Vivaldi, Edge, Opera, Helium), not Google's own Chrome. The same names, recommended by Brichter back in 2020, still serve well in 2026.

The rule I keep is simple. You cannot trust a program that decides to install 4GB of AI weights, or a background updater daemon, without asking you. What is at stake is not just disk space, it is control over what your computer does when you are not looking.

And here we go for the third time

In 2009 Wired called Keystone evil when Google bundled it inside Google Earth. In 2020 Brichter published chromeisbad because the same Keystone was now sitting inside Chrome. Now in 2026 Hanff showed that 4GB of AI weights are being pushed the same way. Between those dates Google only got bigger, and the way it pushes things onto other people's machines without asking has not changed.

I use Brave, and my recommendation is any browser, just not Google Chrome.