IP Leak Test — DNS, WebRTC and IPv6
An IP leak is any path that reveals your real address or DNS resolver while you think a VPN or proxy is covering you. InstantIPCheck checks the public IP, DNS exits and WebRTC candidates on one page.
What an IP leak is
A VPN changes the IP websites see for ordinary HTTPS. It does not automatically change every other channel. DNS queries can still go to your ISP. WebRTC can still gather local or ISP addresses. IPv6 can stay un-tunneled while IPv4 is inside the VPN. Any of those is an IP leak in practice.
How to test for an IP leak
Connect the VPN, then open InstantIPCheck. The homepage IP should match the VPN country, not your broadband. Run the DNS leak test: resolvers should not still be your ISP. Run the WebRTC leak test: candidates should not include your home or office address.
If IPv4 shows the VPN but IPv6 still shows your provider, disable IPv6 in the VPN app or OS until the tunnel covers both.
IP leak versus DNS leak versus WebRTC leak
“IP leak” is the umbrella search. DNS leak is specifically name-resolution leaving the tunnel. WebRTC leak is the browser exposing addresses through peer-connection ICE. InstantIPCheck has dedicated pages for DNS and WebRTC if you want to go deeper, and all three tests start from the homepage.