You may think that your VPN or other anonymity solution keeps your real location private --- but DNS leaks may give you away. Here's a DNS leak test to find out if you're really hidden.
The Internet's DNS system translates domain names like ITWorld.com to numeric IP addresses like 220.127.116.11. Internet servers only understand IP addresses. So when you type in a domain name, the request goes to a DNS server, which translates it to an IP address, and your request goes on its merry way to the Web site.
DNS servers do this translation work. You may be using your service provider's DNS servers, or those run by a third party such as Google or OpenDNS. Those interested in finding out your location can use this DNS information to know where you currently are.
VPNs and other privacy services solve the problem by going through a VPN or similar service before using a DNS server. That way, the DNS information can't be snooped upon.
But in certain circumstanced you can have a DNS leak --- you contact the public DNS server before first going through the VPN. And you won't even know about it.
There's a way to find out. Go to DNSleaktest.com and run either the standard or extended leak test. If you see only the DNS server run by your VPN, you're safe. If you see another one, or multiple ones, you've got a VPN leak. There are several ways to fix VPN leaks --- head here to see them.