Free DNS Leak Test Mechanics

The Role of DNS

The Domain Name System (DNS) translates human-readable domain names (like example.com) into machine-readable IP addresses. By default, your Internet Service Provider (ISP) automatically assigns you their DNS servers. This means they process—and can log—every single website you attempt to visit.

The Anatomy of a Leak

When you connect to a Virtual Private Network (VPN), your system should route all DNS requests through the encrypted tunnel to the VPN provider's secure DNS servers. A "DNS Leak" occurs when an operating system routing error allows DNS requests to bypass the tunnel and go straight to the default ISP servers.

Verifying Tunnel Integrity

Even if your network traffic is encrypted, a DNS leak allows your ISP to see the domain names of every site you visit. Regular testing is imperative to ensure that your configured VPN software is correctly intercepting and tunneling all UDP port 53 traffic.