Quad9
What it's for
An encrypted, Swiss, non-profit DNS resolver that also blocks known malicious domains.
Why it matters
Swiss jurisdiction, no retention of your IP address, protection against phishing and malware. An excellent “set and forget” choice.
For whom & when
Everyone, especially those who want simplicity and a good jurisdiction.
Install & use
On Android: Settings > Network > Private DNS > enter dns.quad9.net.
On iPhone/Mac: install the DoH profile from quad9.net. On PC: set DNS-over-HTTPS in the browser or the system.