Chrome's AI features could be consuming 4GB of storage

Google Chrome might be using more storage than you expect due to a sizable on-device AI model file that, at times, is automatically saved to the browser’s system files. 

Users noticing a sudden reduction in their desktop device’s available storage are finding that Chrome is placing a 4GB weights.bin file in the browser directory when specific AI features are turned on.

The mentioned weights.bin file relates to Google’s Gemini Nano AI model, which powers Chrome’s AI tools such as scam detection, writing help, automatic form filling, and suggestion tools. 

Since Gemini Nano is meant to operate locally, it relies on training parameters stored directly on your device instead of accessing data from cloud-hosted models.

This approach boosts privacy but isn’t ideal if you’re short on space—especially as users aren’t adequately informed about the storage needs.

If particular Gemini AI capabilities are active in Chrome, you probably have the 4GB file on your system already. Check by browsing your Chrome data directory and looking inside the OptGuideOnDeviceModel folder for the weights.bin file.

Merely deleting it won’t free up space permanently—if AI features remain active, Chrome might re-download it later. To prevent this, go to Settings>System and toggle off the On-Device AI option to disable those functions and stop the file from returning.

Google notes that “Gemini Nano’s size can vary with browser updates,” but this info is buried in a detailed guide for AI functions, not directly shared when users enable these tools in Chrome. 

Had Google communicated the storage requirements more clearly—or offered an option to run Chrome AI features using cloud models—this confusion could be avoided. We’ve contacted Google for their input.