All websites have an IP address that is a series of numbers. A DNS or Domain Name System allows us to access a site without having to remember its specific series of numbers. Instead we remember something much simpler such as “Google” or “Amazon”.
Your ISP or Internet Service Provider by default runs its DNS servers. A lot of times this works just fine, and sometimes it doesn’t. And you don’t have to use their servers. There is an option to use third-party DNS servers, like Google Public DNS.
Even as little at 5 years ago your ISP’s default server was usually sufficient to browse the internet efficiently the majority of the time. As web pages get more complex they often pull from dozens if not hundreds of different domain origins. This means your DNS is performing multiple lookups just to display one site. It puts significant stress on the existing DNS structure and over time has slowed down browsing speeds significantly. This is why people often opt to use a public DNS, like Google.
The first advantage to using Google Public DNS is speed, reliability and performance.
Google already crawls the internet regularly and part of the process is to resolve and cache all DNS information. Because of this they are able to support high-volume searches because a big portion of their answers are coming from their cache. This decreases the time needed to answer a query since generally speaking they already have the answer. This also provides more reliability and increased performance, faster query times mean pages load faster and there is less down time. Your ISP can have less stable servers which cause a website to fail to load or load very slowly.
The second advantage to using Google Public DNS is security.
Google Public DNS fully supports DNSSEC or Domain Name Security Extensions which works agains cache poisoning attacks. Cache poisoning is essentially an attempt to redirect users from their intended destination to a malicious site. Sometimes cyber criminals can even take control of an entire DNS zone. With Google Public DNS you get extra security agains these types of attacks. Google Public DNS also offers DNS-over-HTTPS, or DNS resolution over top of and HTTPS connection, which is yet another level of security that prevents eavesdropping, tampering or spoofing.
The last thing to mention is correctness. Google will always return the exact answer to your query, even if you have mistyped or misspelled something. Some ISPs will redirect you and change the direction you are trying to go, and Google won’t.
Google always wants new ways to enhance your browsing experience and provide you with a valuable service. Google Public DNS is a tool to that you can use to hopefully increase the quality of time you spend online.
For configuration instructions, you can visit Google Public DNS Get Started page.