public/free dns:
dns.quad9.net
9.9.9.9
149.112.112.112
2620:fe::fe
2620:fe::9

Recursive DNS Server Addresses and Features - Service based configuration:

Recommended: Malware Blocking, DNSSEC Validation (this is the most typical configuration)

IPv4
9.9.9.9
149.112.112.112

IPv6
2620:fe::fe
2620:fe::9

HTTPS
https://dns.quad9.net/dns-query

TLS
tls://dns.quad9.net

Secured w/ECS: Malware blocking, DNSSEC Validation, ECS enabled

IPv4
9.9.9.11
149.112.112.11

IPv6
2620:fe::11
2620:fe::fe:11

HTTPS
https://dns11.quad9.net/dns-query

TLS
tls://dns11.quad9.net

Unsecured: No Malware blocking, no DNSSEC validation (for experts only!)

IPv4
9.9.9.10
149.112.112.10

IPv6
2620:fe::10
2620:fe::fe:10

HTTPS
https://dns10.quad9.net/dns-query

TLS
tls://dns10.quad9.net