Chrome Quietly Installed a Large AI Model on Your Device

If you use Google Chrome on a desktop computer, there is a strong possibility that a 4GB AI model called Gemini Nano has been silently downloaded onto your machine without your knowledge or consent. This quiet installation occurred between late April and early May 2026, affecting eligible devices running recent versions of the browser. Security researcher Alexander Hanff, known as That Privacy Guy, first flagged this rollout, which offers no consent screen, no pop-up, and no straightforward setting to prevent it. Privacy advocates argue that this practice may violate European data protection laws. Below, we explain how to check your system and remove the file, at least temporarily.

The file in question is Gemini Nano, an AI model designed to run locally on devices like smartphones and laptops rather than relying on cloud servers. According to Hanff, a Swedish computer scientist and lawyer, the model has been installed on some Chrome browsers without user permission. You won’t receive any notification when it lands on your device. Hanff noted that Gemini Nano only installs if your hardware meets specific requirements, though the total number of affected users remains unknown.

This AI model performs tasks such as detecting scam phone calls, helping compose text messages, summarizing recordings, and analyzing Pixel phone screenshots. It should not be confused with the AI Mode feature in Chrome’s address bar. When you use AI Mode, your queries are sent to Google’s Gemini servers, not to the local Gemini Nano. A Google spokesperson told CNET that the model will automatically uninstall if your device lacks sufficient resources, such as processing power, RAM, storage, or network bandwidth.

“In February, we began rolling out the ability for users to easily turn off and remove the model directly in Chrome settings,” the spokesperson said. “Once disabled, the model will no longer download or update.” Google provides more details about on-device generative AI models in Chrome on a dedicated web page.

If you want to reclaim the 4GB of storage space, start by checking whether the model is installed. Hanff emphasized that Chrome users will not know they have Gemini Nano unless they actively search for it, because “Chrome did not ask” and “Chrome does not surface it.” The simplest removal method is to uninstall Chrome entirely.

On a Mac, open Finder by clicking the blue smiling face icon in the dock or pressing Command + N on an empty desktop spot. Click Go in the menu bar, hold the Option key so that Library appears, then select Library. Navigate to Application Support > Google > Chrome > Default. Look for a folder named OptGuideOnDeviceModel. If it exists and contains a file called weights.bin, the AI model is present. To permanently remove it, open Chrome, click the three-dot menu in the top-right corner, go to Settings > System, and toggle off On-device AI.

On a Windows device, use a Run Command by pressing the Windows key and R, then paste in `%LOCALAPPDATA%\Google\Chrome\User Data\OptGuideOnDeviceModel` and press Enter. Check for the weights.bin file. Alternatively, use File Explorer to navigate to `C:\Users\[YourUsername]\AppData\Local\Google\Chrome\User Data\OptGuideOnDeviceModel`. To remove the model, open Chrome, go to Settings > System, and toggle off On-device AI. Next, type `chrome://flags` in the address bar, search for “optimization guide,” and set Enables optimization guide on device to Disabled. Restart Chrome completely by closing it through the menu, not just closing windows. Finally, delete the OptGuideOnDeviceModel folder from `\AppData\Local\Google\Chrome\User Data`.

Hanff suggested that Google’s motivation may be cost-cutting. “Running inference on users’ own hardware allows them to push ‘AI features’ without the compute costs,” he told CNET. However, he warned of potential legal consequences, particularly in Europe. The silent installation could breach the European Union’s General Data Protection Regulation principles of lawfulness, fairness, and transparency. Hanff also argued that, given the environmental impact, Google should have disclosed the move under the Corporate Sustainability Reporting Directive.

“Google has given us every reason not to trust them with a history spanning two decades of global privacy violations at massive scale,” Hanff said. “So, I suspect they figured asking permission (what the law requires) would hinder their ability to push this model and, of course, whatever comes after it.”