Performance comparison of OpenDNS and Google DNS

Google recently launched it’s own Public DNS offering, allowing Internet users to make use of their DNS servers for resolving address queries on the Internet. I have been a fan and user of OpenDNS for quite some time now, which offers the same service with many more options (as compared to Google’s new service). Immediately, I was curious as to how Google’s service compares with OpenDNS.

On a functional and service offering standpoint, I don’t need to really talk about anything, because the founder of OpenDNS already has excellent thoughts on this topic. But he doesn’t talk about the most important metric of all, which is performance. I was curious about how the two compare on pure performance terms. So, sitting in India, I decided to run a quick test myself to measure the performance between the two.

The method is the same as I used when I compared OpenDNS with Airtel, my local ISP in India. I basically measured lookup times of 100 random domains and compared the two DNS on that metric. Here are my findings.

The graph below plots the query response time for both the DNS services for 100 random domains. What we can see from the graph already is that neither one is clearly faster than the other.

Google DNS vs Open DNS

Here’s another graph which gives clarity on which one is faster more often:

Google DNS vs OpenDNS

As we can see, they are almost the same. So, how do we know which is better or faster?

I took a look at the average of the measurements for the two services, and this is what I found:

  • OpenDNS – 0.38
  • Google Public DNS – 0.41

This means that on average, OpenDNS is slightly faster than Google. However, as we can see there are 3 spikes in the Google Data, and one in the OpenDNS data. When I remove those, the average for the two is almost the same (with OpenDNS being marginally slower).

Another thing worth noting however is the Standard Deviation – the measure which tells us how often will the measurement fall close to the average performance. This can even be surmised by the first graph. With the complete measurements, the Standard Deviation of Google was about 3 times that of OpenDNS, and even with the spikes removes, the standard deviation of Google was twice that of OpenDNS. Which means that OpenDNS on the whole is more consistent in its operation.

This means that when Google is deviating on the faster side, it will be much faster than OpenDNS, but when it deviates on the slower side, it will be much slower than OpenDNS (on average).

At this stage, I will have to say that I cannot conclude, though I would like to think that OpenDNS is a better performer for providing consistent performance, as compared to Google Public DNS. But with Google’s muscle, I am sure that it will eventually surpass OpenDNS on these parameters. Who knows, maybe Google will buy OpenDNS (although I am not sure if they will be selling).

38 thoughts on “Performance comparison of OpenDNS and Google DNS”

  1. More important difference is that Google’s service works 100% as standard says, returning NXDOMAIN on nonexisting domains instead of redirecting to a spammy ad-page like OpenDNS does.

    1. Well yes, that is always a contention with OpenDNS. However, I typically ignore their page when that happens, anyway, as I am guessing most of the users do.

      It is very clear, since it says OpenDNS on the very top :)

      1. I agree. I very seldom ever see their page. Maybe i’m just a good typer? Plus, running Firefox with adblocker you don’t see the ads anyway.

  2. I think that i give enough information to Google by using their services and i’m not sure if i’ll use their DNS too.

    1. Personally, I don’t care about my data on Google. But I think OpenDNS is a better functional package at this time with similar performance measures to Google

  3. Just to note about too much paranoia: the privacy policy on DNS service stats that this information is not linked to any Google account in any way and IP information is purged within 48 hours.

  4. Thanks for the really interesting post. I’ve been testing OpenDNS for a while but since I’m a huge fan of Google’s approach to most things I reckon I’ll check out their DNS services too. Yes, they know a lot about me but since it usually enhances my life I’m really not bothered 😉

    1. I agree. I think Google will overtake soon enough anyway – Google has the infrastructure to make this DNS local in most geographies too..

  5. 3 spikes in a hundred points isn’t really enough spikes to make a conclusion about said spikes. Would be cool to redo the test with something like 5000 data points (thus should be nearer 100 spikes). As well as doing this every hour to see how performance varies with overall load (ie. America wakes up, America goes back to sleep, etc.)

    1. You are right, I should do this for a larger data set too… However, I did mention the data without the spikes, and Google DNS still has more standard deviation.

  6. I tried Google Public DNS and its fast
    My report shows almost 50% less latency but when I changed name server for one of domain
    it took time to reflect that changes on my local PC and as soon as I changed it to Open DNS
    I can see name server change

    1. I have noticed that in the past too… Although, this can’t be conclusive, but OpenDNS does reflect a changed DNS pretty quickly.

      Did you say that Google DNS was 50% faster in general or when compared to OpenDNS?

  7. I am pleased to read your Post Vaibhav. Its the only article I cam across after reading some 10 or so posts on GoogleDNS Vs OpenDNS.

    The brevity and conclusiveness with which you have written the above and some graphs and charts thrown in are just what a nerd needs to make his day complete.

    Articles like these are hard to come by and well, please be good enough to suggest me some more people whom you follow.

    Gives me courage to read about SNMP now. Sweet :)

  8. I am a very happy user of openDNS and have no intention of leaving for an upstart. openDNS has other services that make it worth staying with them, so if you don’t know what that means, check them out before deciding for yourself if you really need an independent DNS service.

    1. I am surprised that a Google backed service would be termed as an “upstart”.

      I agree with you on the value added proposition that OpenDNS has makes it worthwhile sticking with them.

  9. First time reader of the site, but to the topic at hand…I currently run 3 different DNS at different locations and even some on the same network provider yield different results. So you as a person should look for what works for each individual location. That being said alot of people will more than likely use the GoogleDNS because of the name. I just dont see myself leaving OpenDNS for my home and my next choice would be Ultra. Im trying to avoid everything google. IMHO bing is a superior search engine these days and google documents cant replace office/iwork so there is no reason for me to suffer with the crazy amount of trash adds and their weighted search results. Don’t know if anyone else feels same way, but its getting harder to get good information off page 1 these days because of how results are now

    /end rant

  10. FOOLDNS:
    That dns blocks AD with any browser and any applications
    try it its dns from europe germany and italy

  11. I simply could not leave your site prior to suggesting that I actually loved the standard information an individual provide to your guests? Is going to be again ceaselessly in order to investigate cross-check new posts

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