If you’ve been paying attention to Google lately, you know that it wants us to use its AI tools. So much so that Chrome apparently downloads a 4GB file containing details about running Gemini Nano, Google’s built-in LLM. Computer scientist Alexander Hanff published the details earlier this week on his website The Privacy Guy and explains in detail why this is not a good idea for Google.
I just checked what it said about the file, named “weights.bin” and found it in the Chrome folder in the macOS library directory (which is usually hidden so users don’t handle potentially critical files). Indeed, it is a 4GB+ file where he said it would be. Hanff rightly notes that at no point does Chrome prompt users if they want to install Gemini Nano weights, which Chrome users use for AI-based features like “help me write” and on-device scam detection.
Google provided Engadget with the following statement after this story was initially published:
“We offered Gemini Nano for Chrome since 2024 as a lightweight, in-device model. It powers important security capabilities such as scam detection and developer APIs without sending your data to the cloud. Although it requires some local desktop space to work, the template will automatically uninstall if the device runs out of resources. In February, we began offering users the ability to easily disable and remove the template directly in Chrome settings. Once disabled, the template will no longer be downloaded or updated. 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 colleague’s laptop. Shortly after updating Chrome to version 148.0.7778.97 on my home 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 came back several minutes later.
Hanff wrote that he also saw similar behavior on several Windows installations. “User deletes, Chrome redownloads, user deletes again, Chrome redownloads again. The only ways to make the deletion persist are to disable Chrome’s AI features via chrome://flags or corporate policy tools that home users typically don’t have, or to uninstall Chrome altogether.”
It’s important to note that Hanff appears to have missed the relatively simple uninstall option provided by Google in its settings. If you go to Chrome’s Settings and then click “System” in the left menu, there is an option to disable AI features on the device.
Hanff also warns that this could violate European privacy laws, including GDPR. There is also the potentially significant environmental cost. Hanff estimates that a “mid-band” deployment of this 4 GB file would reach 500 million devices, or about 15% of Chrome users. This initiative would result in the production of around 30,000 tonnes of CO2 equivalent, or the annual emissions of 6,500 cars. He also notes that this is just the initial delivery cost and many additional factors would result in a higher energy cost.
Updated, May 6, 2026, 1:35 p.m. ET: This story has been updated with Google’s statement and to note that Chrome has provided a way to disable AI tools on the device since February.