Chrome downloads a 4GB file for Gemini Nano without explicit user consent, researcher reports

Computer scientist Alexander Hanff published findings that Chrome automatically downloads a 4GB file named "weights.bin" containing Gemini Nano (Google's on-device LLM) to users' devices without prompting them for permission. The file enables AI-powered features like "help me write" and on-device scam detection.

Google states that Gemini Nano has been offered since 2024 and that users have been able to turn off and remove the model directly in Chrome settings since February. The company notes the model automatically uninstalls if device resources are low and that once disabled, it will no longer download or update.

Hanff estimates that a "mid-band" deployment of this 4GB file to 500 million devices (approximately 15 percent of Chrome users) would result in roughly 30,000 tonnes of CO2e — the annual emissions of 6,500 cars. He also raised concerns that the practice may violate European privacy laws, including GDPR.