Android 9 and higher comes with the "Private DNS" feature, which allows you to connect to DNS servers using DNS over TLS (DoT). It is important to note, that the private DNS function does not work if the Quad9 Connect app is installed and enabled. To configure your Android device to use Quad9 in this way, follow the steps below.
Open Settings on your Android device.
Select Network & Internet from the menu
Select Advanced at the bottom of the Network & internet screen.
Select Private DNS.
Select private DNS provider hostname and enter the appropriate Quad9 tls_auth_name for your needs. Once you have the addresses entered, select save.
For more information on which tls_auth_name is right for you, please visit our Quad9 IPs and Other Settings page.
Most users will want to enter dns.quad9.net