Web Pages Not Loading? Here's How to Change Your Mac's DNS Servers

Comcast's customers learned the hard way yesterday that sometimes Internet connections aren't as reliable as we'd like. In this case, it was Comcast's DNS servers that failed, leaving users stuck without any way for their browsers to find Web pages. This problem can happen with any Internet Service Provider, but you can cut down on the chances of it happening to you by switching to more reliable DNS servers. Bonus: It'a easy to do. Read on to learn how.

DNS servers, or Domain Name Servers, convert the URLs you type into the string of numbers that makes up a site's actual server address. Typing "apple.com" in Safari, for example, takes you to Remembering apple.com is much easier, and it's DNS servers that handle the conversion from friendly URLs into IP addresses.

If your DNS server fails, it's akin to losing your babel fish while wandering the streets of Brantisvogon: the words are all still there, but you can't understand what they mean.

Since DNS servers are so critical to navigating the Web, it makes sense to find ones that are reliable. I recommend OpenDNS (just as I have been doing for years), and alternatively, Google. Here are their IP addresses:

Open DNS




Here's how to replace the default DNS servers Comcast, Time Warner, CenturyLink, and other ISPs give you:

  • On your Mac go to Apple menu > System Preferences
  • Select Network
  • If the padlock in the lower left corner of the window is locked, click it and enter your administrator account password

Click Advanced to get at your Mac's DNS settingsClick Advanced to get at your Mac's DNS settings

  • Click Advanced, then select the DNS tab
  • Now click the plus symbol button under the DNS Servers column
  • Add the DNS servers you want to use. I added OpenDNS and Google's DNS servers so I always have a fall back in the unlikely chance that one is temporarily off line
  • Click OK

Replace your ISP's DNS entries with OpenDNS and GoogleReplace your ISP's DNS entries with OpenDNS and Google

That's it. Now you're using reliable DNS servers that are also very likely to be faster than the servers your ISP provides. Even better: When your ISP's DNS servers go down you'll find out about it on Twitter instead of wondering why Web pages aren't loading.