Best Free Public DNS Servers

 Google Public DNS

Google being Google, they have massive scale, load-balancing, redundancy and DNS servers distributed all over the world. They also support the latest technologies and security mechanisms like IPv6 DNS servers and DNSSEC. Their DNS servers are also well protected against DoS attacks and cache poisoning attacks.
It’s worth noting that Google Public DNS does not perform any blocking or filtering on the DNS requests, as some of the other services do. They state that only under extraordinary circumstances would they block anything. For me, this is a good option because I use other tools to filter out malware sites, etc and don’t necessarily want my DNS service to be involved.
The main benefit for using Google is their global data center and the fact that they have DNS servers located around the world. Some other services only have DNS servers located in one part of the world, so the performance will suffer considerably.
The main downside to using Google is that they are all about tracking and logging everything anyone does on the Internet and this is no exception. If you are leery of Google having too much information, I would suggest using a different DNS server.
Google Public DNS IPv4 Addresses
8.8.8.8

8.8.4.4
Google Public DNS IPv6 Addresses

2001:4860:4860::8888
2001:4860:4860::8844