When your computer or router is connected to the internet through DHCP (Dynamic Host Configuration Protocol), your Internet Service Provider (ISP) automatically assigns DNS servers for this purpose.
Instead of going that way, you can choose to use any of the free and public DNS servers described below. These are the Top 7 public and free DNS:

• Google https://www.dnsperf.com/dns-resolver/google: Google public DNS is a free, global Domain Name System (DNS) resolution service. Its primary DNS Server’s IP address is 8.8.8.8, and its secondary DNS Server’s IP address is 8.8.4.4. It speeds up your browsing experience with no redirection. And it is secured.
• Level3: This is a third-party DNS Service that is free and open to the public. Its infrastructure, though great and reliable, is not as huge (big) as Google’s. Its primary DNS Server’s IP address is 209.244.0.3, and its secondary Server’s IP address is 209.244.0.4.
• VeriSign https://www.dnsperf.com/dns-resolver/verisign: This is also a public and free DNS service, and it is popular among internet users because it offers protection against online threats and malware. Verisign also provides customized DNS filtering and advanced system for detecting threats. Its primary DNS Server’s IP address is 64.6.64.6, and its secondary Server’s IP address is 64.6.65.6.
• DNS. Watch: This is considered to be uncensored and fast. It is a public Domain Name System, meaning it is available for free use all over the world. Its primary DNS Server’s IP address is 84.200.69.80, and its secondary DNS Server’s IP address is 84.200.70.40.
• Comodo Secure DNS https://www.dnsperf.com/dns-resolver/comodo: As a public DNS service, it is available for free. Comodo secure DNS is regarded to be more reliable when compared with some other DNS services; and, it is fast, safe, and smart. It is easy and quick changing to Comodo secure DNS from other DNS services. Its primary IP address is 8.26.56.26, and its secondary IP address is 8.20.247.20.
• OpenDNS Home https://www.dnsperf.com/dns-resolver/opendns: OpenDNS Home is a public DNS service, and it is available for free. It reportedly has the capability to predict cyberattacks before they happen. It provides noticeably fast internet connection, and offers security intelligence as well as web filtering. Its primary DNS Server’s IP address is 208.67.222.222, and its secondary Server’s IP address is 208.67.220.220.
• Norton ConnectSafe https://www.dnsperf.com/dns-resolver/norton: Norton ConnectSafe is public and free, and it provides web filtering service that allows users to choose what kind of threats they will like to filter. These threats may include malware, spyware, and other threats from malicious sites with unwanted or offensive content. Its primary DNS Server’s IP address is 199.85.126.10, and its secondary Server’s IP address is 199.85.127.10.

Even though all Top 7 DNS servers described above are public and free, they do have different characteristic features and functionalities. Here are some of the criteria you should consider while selecting the best DNS server for your internet usage:

• Speed—is it fast enough?
• Safety—are there some safety features to protect one’s internet browsing?
• Filtering system—does it have an effective web filtering system?
• Reliability—is it reliable?
• Durability—can I use it for a long period of it?

Use www.dnsperf.com to decide what is best for you.