Quad9 is described as 'free, recursive, anycast DNS platform that provides end users robust security protections, high-performance, and privacy' and is a DNS Resolver in the Network & Admin category. There are more than 25 alternatives to Quad9 for a variety of platforms, including Online / Web-based, Windows, Mac, Linux and Android. The best alternative is 126.96.36.199, which is free. Other great apps like Quad9 are NextDNS (Freemium), OpenNIC (Free, Open Source), OpenDNS (Freemium) and DNSCrypt Protocol (Free, Open Source).
188.8.131.52 from CloudFlare is the fast and private way to browse the Internet. It is a public DNS resolver, but unlike most DNS resolvers, 184.108.40.206 is not selling user data to advertisers. The implementation of 220.127.116.11 makes it the fastest resolver out there.
DNSCrypt is a protocol that authenticates communications between a DNS client and a DNS resolver. It prevents DNS spoofing. It uses cryptographic signatures to verify that responses originate from the chosen DNS resolver and haven't been tampered with.
SafeDNS provides sophisticated cloud-based and software solutions for web content filtering which increase users' safety online by blocking botnets, malware and phishing resources, filter out most advertising and content users consider inappropriate.
Yandex.DNS is a free, recursive DNS service. Yandex.DNS' servers are located in Russia, CIS countries, and Western Europe. Users' requests are processed by the nearest data center which provides high connection speeds.