This article assumes you know what DNS is and may be interesting optimizing it.
There are many public DNS providers and by default you are probably using your ISP’s DNS servers. There are many reasons you may not want to use your ISP’s DNS servers, but this is mainly focused on speed/performance.
In many cases, your ISP may be the fastest and as such, changing it may degrade your page load times (specifically the DNS resolution time). However, some ISPs may have slower DNS servers, and you may gain a nice little bump by switching to a public one.
Before blindly changing to one of the well known DNS providers, I recommend that you run a benchmark so you know who will perform the best for you.
Unfortunately, there aren’t many options for good DNS benchmarking tools. If you are using OS X or Linux, I recommend you use namebench. It is an unmaintained python project that does a reasonable job:
If you are using Windows, you may find DNS benchmark an easier solution than trying to run namebench:
Here is a list of public DNS providers I found at ghacks you could test. Depending on where you are located, you may be able to find regional DNS servers that perform better than these. You will need to do some digging to find them though.
DNS Advantage: 22.214.171.124, 126.96.36.199
Dyn DNS: 188.8.131.52, 184.108.40.206
Google DNS: 220.127.116.11, 18.104.22.168
Open DNS Home: 22.214.171.124, 126.96.36.199
Censur Fri DNS: 188.8.131.52, 184.108.40.206
Comodo Secure DNS: 220.127.116.11, 18.104.22.168
DNS Watch: 22.214.171.124, 126.96.36.199
Free DNS: 188.8.131.52. 184.108.40.206
Green Team DNS: 220.127.116.11, 18.104.22.168
Level 3: 22.214.171.124, 126.96.36.199
Norton ConnectSafe: 188.8.131.52, 184.108.40.206
Open Nic: 220.127.116.11, 18.104.22.168
Safe DNS: 22.214.171.124, 126.96.36.199
Smart Viper: 188.8.131.52, 184.108.40.206
After running the benchmark, if you find a faster or equivalent provider to your ISP, you should consider configuring your network settings to use the preferred provider. Share your results in the comments!