Virtually every bit of Internet data requested by a computer starts with a DNS lookup. The human-readable address (www.mackungfu.org, for example) is converted to the numeric IP address for use on the Internet (126.96.36.199, for example).
DNS lookups take milliseconds but in our impatient world this can add-up to a noticeable delay. For many years people have been switching to much faster public DNS servers, such as those provided by Google or OpenDNS. However, the superb (and free!) Namebench utility for Mac – created by a Google engineer – can help find the very fastest public DNS for you in your particular geographic location. Put simply, it benchmarks your current DNS along with several public services in order to find the fastest.
Using the app is easy. Install it by dragging it to your Applications list, then right-click the app icon and select Open. Then choose to open the app. Namebench will fill in most details automatically but, unless you’re a Google Chrome user, I suggest selecting Top 2,000 Websites (Alexa) from the Query Data Source dropdown list.
Additionally, if your ISP censors your connection – if it blocks access to access certain torrent sites, for example – then you can put a check in the Include Censorship Checks box to further filter the results.
Once done, click the Start button. Namebench takes a long time to complete – just leave it running in the background.
When Namebench has finished it’ll open a web page showing the results. A lot of info is provided but all you really need is at the top right of the page, where suggested primary, secondary and tertiary DNS server addresses are listed as numeric IP addresses. Make a note of these.
Changing your DNS settings
Taking the information you made a note of above, open System Preferences, select the Network icon, then click the Advanced button. Click the DNS tab, and then the plus button at the bottom left of the list. Type or paste-in the first DNS address, hit Enter, then click the plus button again to enter the second. Doing this will overtype any default entries in the list, so there’s no need to manually delete them.
Add the tertiary (third) address if needed, although there’s not really any need – a primary and secondary are fine for most situations.
Note that if you use two or more different types of Internet connection – Wi-Fi along with Ethernet for example – then you’ll need to do this for each connection by selecting it at the left after you click the Network icon in System Preferences.
If your router allows it, you might also change the DNS settings within its configuration pages, which will mean that all devices in your household benefit from faster DNS lookups.
Try to run Namebench once a month to ensure you keep up with the fastest possible servers.
If you use public wi-fi services while out and about then you might need to temporarily delete your new DNS settings because they can interfere with the captive portal technology these services use. Just add them again when you return home. Alternatively you can create alternate network locations for home and public wi-fi.