Google Wifi collects and uses data as explained here, including information about the types of connected devices you have and their network usage. The cloud services, Wifi point stats, and app stats data described here (which we refer to as “Wi-Fi network performance data”) is not used for ad personalization. We may use this data to keep you informed about updates on Google services, including connected home devices and services we think may help you — such as an additional Wifi point to improve your internet connectivity. You can opt out from certain portions of this data collection as explained here.
Google Wifi does not track the websites you visit, nor does it monitor the content of traffic on your Wi-Fi network. Google Wifi sets your default DNS provider to “Automatic,” which uses Google Public DNS or your Internet Service Provider’s (ISP) DNS if certain conditions are met. More info on what Google Public DNS collects can be found here. You can change your DNS provider in the Advanced Networking settings of the Google Home app at any time.