Google Chrome silently downloads large AI model, raising privacy concerns

As detailed in HackRead, a cybersecurity researcher has uncovered that Google Chrome is downloading a substantial AI model, Gemini Nano, onto users' computers without explicit consent. This discovery raises significant questions about user privacy and the energy consumed by such background data transfers.

Cybersecurity researcher Alexander Hanff discovered that Google Chrome is downloading a 4GB AI model, Gemini Nano, onto users' machines if they meet certain hardware requirements. The download occurs silently in the background during idle times, initiated by the browser itself without any user interaction. Hanff's tests, conducted on a clean Chrome profile on macOS in April 2026, confirmed the browser created an "OptGuideOnDeviceModel" folder and downloaded the "weights.bin" file within 14 minutes.

Google states the model aids in features like scam detection, but the method of distribution raised concerns among critics. Hanff estimates that if 100 million users download it, the energy consumption would be 24 GWh, escalating to 240 GWh if it reaches 30% of Chrome's user base. Furthermore, Hanff argues this silent installation potentially violates the EU ePrivacy Directive and GDPR, which mandate transparency and consent for data storage on user devices. He cited breaches of Article 5(3) of the ePrivacy Directive and GDPR principles, including lawfulness, fairness, transparency, and data protection by design.

A similar issue was noted with Anthropic's Claude Desktop app. Users can check for the model at "chrome://on-device-internals" and disable it via Chrome Settings or "chrome://flags".

Source: HackRead