Chrome Installs 4 GB Gemini Nano Model Without User Consent

Context Security researcher Alexander Hanff discovered that Chrome creates a folder named *OptGuideOnDeviceModel* and fills it with a file called *weights.bin*. The file size totals roughly 4 GB and contains the Gemini Nano model, a lightweight version of Google’s large language model designed to run locally.

Key Facts - Chrome adds the model to any device that meets minimum hardware specs without prompting the user for permission. - Google states Gemini Nano has been bundled with Chrome since 2024 to power on‑device features such as scam detection, keeping data out of the cloud. The model occupies local storage and can auto‑uninstall when system resources are low. - In February, Google rolled out a setting that lets users disable or remove the model via Chrome → Settings → System → “Turn on‑device AI on or off.” - Hanff reports that if a user manually deletes the *weights.bin* file, Chrome automatically re‑downloads the model after each restart, a behavior observed on both Windows and macOS. - Users can block the re‑download by disabling AI‑related flags at *chrome://flags* or by making the file read‑only, though doing so may impair AI features.

What It Means The silent installation raises questions about consent and transparency in software that handles personal data. While Google frames the model as a security tool, the automatic re‑installation bypasses the user’s explicit choice, effectively forcing storage use and potential performance impact. The recent opt‑out option offers a remedy, but it only appears for browsers that have received the February update, leaving many users without a straightforward way to opt out.

Watch for Chrome updates that may expand the opt‑out feature or alter the default behavior of on‑device AI models.