DNS Leak Test
A DNS leak test is a diagnostic tool that checks whether your DNS queries are being sent outside your VPN tunnel to your ISP's servers.
The test works by triggering DNS queries from your browser and detecting which resolvers respond. If the responding servers belong to your ISP instead of your VPN provider, your DNS traffic is leaking outside the VPN tunnel, exposing every domain you visit to your ISP despite the VPN being active.
Frequently Asked Questions
What is a DNS leak?
A DNS leak occurs when your device sends DNS queries outside your VPN tunnel, directly to your ISP's DNS servers. This allows your ISP to see every domain you visit even though your VPN is active.
How do DNS leaks happen?
DNS leaks happen when your operating system uses its default DNS resolver instead of the one provided by your VPN. This can occur due to misconfigured VPN clients, split tunneling, or Windows features like Smart Multi-Homed Name Resolution.
How can I tell if I have a DNS leak?
Run a DNS leak test at whatismyip.technology/tools/dns-leak-test. If the DNS servers shown belong to your ISP rather than your VPN provider, you have a leak.
How do I fix a DNS leak?
To fix a DNS leak: configure your VPN to use its own DNS servers, disable IPv6 if your VPN does not support it, set your DNS to a privacy-focused resolver like 1.1.1.1 or 9.9.9.9, and enable your VPN's kill switch.
DNS Leak Test
Is your DNS sneaking out behind your VPN?
Even with a VPN on, your DNS requests can slip outside the tunnel and rat out your real ISP and location. This test catches that.
Checking DNS servers…
How DNS leaks happen. Windows "Smart Multi-Homed Name Resolution" sends DNS to all interfaces simultaneously — including your real ISP — bypassing your VPN. Use a VPN with DNS leak protection to prevent this.