If you've paid any attention to Google lately, you know that it wants us using its AI tools. So much so that Chrome apparently downloads a 4GB file containing details for running Gemini Nano, Google's on-device LLM. Computer scientist Alexander Hanff published the details earlier this week on his website The Privacy Guy and goes into extreme detail on why this isn't a good look for Google.
I just verified what he said about the file, named "weights.bin" and found it in the Chrome folder in the macOS Library directory (which is ordinarily hidden so that users don't mess with potentially critical files). Indeed, it's a 4+ GB file right where he said it would be. Hanff correctly notes that at no point does Chrome prompt users to ask if they'd like to install the Gemini Nano weights, which Chrome users for AI-powered features like "help me write" and on-device scam detection.
Google provided Engadget with the following statement after this story was originally published:
"We've offered Gemini Nano for Chrome since 2024 as a lightweight, on-device model. It powers important security capabilities like scam detection and developer APIs without sending your data to the cloud. While this requires some local space on the desktop to run, the model will automatically uninstall if the device is low on resources. In February, we began rolling out the ability for users to easily turn off and remove the model directly in Chrome settings. Once disabled the model will no longer download or update. More details in our help center article."
It's worth noting that on a second Mac I checked, the weights.bin file was not installed, nor was it found on a coworker's laptop. Shortly after updating Chrome to version 148.0.7778.97 on my personal laptop, the directory and file appeared. And when I deleted the directory containing the file on the first computer I checked, the large weights.bin file returned several minutes later.
Hanff wrote that he saw similar behavior across multiple Windows installations, as well. "The user deletes, Chrome re-downloads, the user deletes again, Chrome re-downloads again. The only ways to make the deletion stick are to disable Chrome's AI features through chrome://flags or enterprise policy tooling that home users do not generally have, or to uninstall Chrome entirely."
It's important to note that Hanff appears to have missed the relatively uninstall option that Google points out in its settings. If you go to Chrome settings and then click "system" on the left-side menu, there's a toggle to turn off on-device AI features.
Additional issues that Hanff calls out includes that this may violate European privacy laws, including GDPR. There's also the potentially large environmental cost. Hanff estimates that a "mid-band" deployment of this 4GB file would hit 500 million devices, or about 15 percent of Chrome users. That push would result in rough 30,000 tonnes of CO2e — the annual emissions of 6,500 cars. He also notes that this is only the initial delivery cost and that plenty of additional factors would make for a higher energy cost.
Update, May 6, 2026, 1:35PM ET: This story has been updated with Google's statement and to note that Chrome has provided a way to turn off on-device AI tools since February.
