Google Public DNS

Google made a big splash last week when it announced Google Public DNS. By changing your DNS settings on your Mac, PC or router you can take advantage of Google’s DNS service and speed up your internet experience. That’s the theory but does it work? First off, what is DNS?

DNS takes the meaningful domain names that you type in your browser and turns that into a numerical identifier that computers understand. An analogy that is often made is DNS is the phone book for the internet. Wikipedia has more if you want to delve deeper. With that out the way onto some testing. My current ISP is O2 but I actually use OpenDNS for DNS lookups. They’ve proven to be faster than my previous two ISP’s but I was interested in comparing O2, OpenDNS and Google Public DNS. To do that I followed the advice on TechSutra and ran the following code:

for i in "" "" "" "" "" "" "" "" ""
for j in "" "" ""
echo $j $i `dig @$j $i | grep Query | awk -F ":" '{print $2}'`

This basically compared the lookup time for the three DNS providers for a variety of sites that I used daily. The results of the test can be seen in the table below:

Domain O2 Google OpenDNS 111ms 69ms 29ms 179ms 36ms 27ms 28ms 36ms 27ms 28ms 55ms 29ms 28ms 34ms 27ms 28ms 35ms 27ms 160ms 38ms 28ms 28ms 35ms 30ms 29ms 35ms 28ms

As can be seen OpenDNS provided by far the best speeds out of the three I tested. I ran the test a few times and took average times to rule out any issues but the results were fairly consistent. Another method of testing is to try Namebench. This is a Google 20% app for Mac, PC and Linux. It compares a list of known DNS providers against your current DNS provider and provides a set of graphs and charts allowing you to benchmark any potential gains. It’s very slick.

My findings which seem to be backed up by others is that OpenDNS, for UK users, is a better option for speed than Google Public DNS. Do remember though that OpenDNS does redirect certain sites to protect from malware and domain misspellings, serving up adverts at the same time. In comparison Google offers no redirects at all which many people prefer.

The speed differences you do see may look small but remember that every little bit helps to improve your browsing experience and switching to a fast and reliable DNS provider can make a noticeable difference in your day to day usage.

So did you change your DNS after testing? We’d love to hear who you switched to and your findings – leave a comment below.