Leaks that defeat a VPN
A VPN only protects you if all your traffic goes through the tunnel. Two common leaks break that promise:
- WebRTC leaks expose your real public IP through the browser, even with a VPN connected. The test above catches these.
- DNS leakssend your lookups to your ISP's resolver instead of the VPN's, revealing the sites you visit.
How to check your DNS resolver
A precise DNS-leak test needs special server infrastructure to see which resolver answered your request, so the most reliable check is your VPN provider's own leak-test page, or a dedicated DNS-leak service. Make sure your VPN's DNS-leak protection is switched on.
Related: run a VPN check, the IP leak test, or read how to test your VPN.
Frequently asked questions
What is a DNS leak?
A DNS leak happens when your device sends DNS lookups outside the VPN tunnel, usually to your ISP's resolver. Even with a VPN hiding your traffic, that can reveal which sites you visit.
What is a WebRTC leak?
WebRTC is a browser feature that can discover your real public IP for peer connections, sometimes bypassing the VPN. The test above checks for this directly in your browser.
How do I confirm my DNS isn't leaking?
The most reliable way is your VPN's own leak-test page or a dedicated DNS-leak service, because checking the resolver behind your requests needs special test infrastructure. Most good VPNs include DNS-leak protection you can enable in settings.
How do I fix a leak?
Enable your VPN's leak protection and kill switch, disable WebRTC in your browser or use an extension that blocks it, and prefer the VPN's built-in DNS. Then re-run the test.