What is a DNS Leak?

Every time you visit a website, your device needs to translate the domain name (like google.com) into an IP address that computers understand. This translation happens through the Domain Name System (DNS). Think of DNS as the internet's phone book, matching names to numbers so your browser knows where to go.

A DNS leak occurs when your DNS queries bypass your VPN or proxy, exposing your browsing activity to your internet service provider or third parties.

How DNS Leaks Happen

When you connect to a VPN, all your internet traffic should flow through an encrypted tunnel. However, DNS requests sometimes take a different path, going directly to your ISP's DNS servers instead. This creates a gap in your privacy protection that many users never realize exists.

Operating System Configuration: Your computer may have hardcoded DNS settings that override your VPN's configuration, causing queries to leak outside the encrypted tunnel.
IPv6 Traffic: Many VPNs only protect IPv4 traffic, leaving IPv6 DNS queries exposed. If your network supports IPv6, these requests might bypass your VPN entirely.
Transparent DNS Proxies: Some ISPs intercept all DNS traffic on port 53& regardless of which DNS server you specify, routing it through their own servers instead.
Smart Multi-Homed Name Resolution: Windows uses a feature that sends DNS queries to all available network adapters simultaneously, potentially sending requests outside your VPN.

Why DNS Leaks Matter

⚠ A DNS leak reveals every website you visit, even when using a VPN

Your DNS queries create a detailed log of your online activity. Every website you visit, every service you use, and every app that connects to the internet generates DNS requests. When these queries leak, they provide a complete picture of your browsing habits to anyone monitoring the traffic.

Internet service providers commonly collect and sell this data to advertisers and data brokers. In some countries, ISPs are required to log and retain DNS queries for government surveillance purposes. Even if you trust your ISP, the data could be exposed through security breaches or legal requests.

For anyone using a VPN for privacy reasons, a DNS leak completely undermines that protection. Your encrypted VPN traffic might hide the content of your communications, but the DNS leak tells observers exactly where that traffic is going. Check your IP address to see what other information websites can learn about you.

Preventing DNS Leaks

Choose a VPN with Built In DNS Protection: The best VPN services operate their own DNS servers and ensure all queries route through their encrypted tunnel automatically.
Configure Manual DNS Settings: Set your computer to use trusted third party DNS servers like Cloudflare (1.1.1.1), Google (8.8.8.8), or Quad9 (9.9.9.9) while your VPN handles the routing.
Enable DNS over HTTPS (DoH): Modern browsers support encrypted DNS, which prevents your ISP from seeing or intercepting your DNS queries even without a VPN.
Disable IPv6: If your VPN does not support IPv6, consider disabling it on your network adapter to prevent traffic from leaking through that protocol.
Use a Firewall: Configure your firewall to block all DNS traffic that does not go through your VPN, preventing any possibility of leaks.

VPN and DNS Protection

Not all VPNs handle DNS equally well. Free VPNs rarely include proper DNS leak protection, and even some paid services have imperfect implementations. When evaluating a VPN for privacy, DNS protection should be one of your primary criteria.

A quality VPN should automatically configure your DNS settings when connected, routing all queries through their own private DNS servers. This ensures that even if something goes wrong with the tunnel, your DNS queries remain protected. Look for VPNs that explicitly advertise DNS leak protection as a feature.

Always test your VPN for DNS leaks after setup and periodically thereafter. VPN software updates, operating system changes, and network configuration adjustments can all potentially introduce leaks. Running this test regularly helps ensure your privacy remains intact. You might also want to check for WebRTC leaks, another common way your real IP address can be exposed.

Understanding Your Results

When you run this DNS leak test, we identify which DNS servers are handling your queries and compare them against what we know about your connection. The results show you exactly where your DNS requests are going and whether there might be a privacy concern.

No Leak Detected: Your DNS queries appear to be routed securely. If you are using a VPN, the DNS servers should belong to your VPN provider or a trusted third party.
Potential Leak Detected: We found DNS servers that may indicate your queries are not fully protected. This often means requests are going to your ISP instead of through your VPN.
Server Details: Each detected DNS server shows its IP address, hostname, ISP, and location. Compare these against your VPN provider to verify proper protection.

If you see your ISP's name in the DNS server list while connected to a VPN, that is a clear sign of a DNS leak. The fix usually involves adjusting your VPN settings, changing your DNS configuration, or switching to a VPN with better leak protection. After making changes, run this test again to confirm the leak is resolved.

DNS Leak Test