Google Chrome Silently Installs 4GB Gemini Nano Model Without User Consent

The Silent Install

Google Chrome is writing a 4GB file named weights.bin into a directory called OptGuideOnDeviceModel on user devices without any consent dialog. The file contains weights for Gemini Nano, Google's on-device LLM powering features like 'Help me write' and on-device scam detection.

Self-Reinstalling After Deletion

Multiple independent reports confirm a deletion-and-redownload cycle on Windows. On macOS, Chrome's internal state means it redownloads as soon as Chrome's variations server reasserts eligibility. The only reliable remedies are disabling AI features via chrome://flags, using enterprise policy tools, or uninstalling Chrome entirely.

Verified via macOS Kernel Events

Privacy researcher Alexander Hanff confirmed the behavior on a fresh audit profile that received zero human input. On April 24, 2026, Chrome spawned three concurrent unpacker subprocesses and wrote 4GB of model weights. The macOS .fseventsd filesystem event log provided byte-precise timestamps independent of any application logging.

Legal and Environmental Concerns

Hanff argues this constitutes a breach of Article 5(3) of the ePrivacy Directive, GDPR Article 5(1) principles of lawfulness and transparency, and GDPR Article 25 data-protection-by-design obligations. At Chrome's scale of roughly two billion devices, a single model push represents an estimated 6,000-60,000 tonnes of CO2-equivalent emissions.