Many VPNs only tunnel IPv4 traffic. If your device has working IPv6 connectivity, websites can see your real IPv6 address around the VPN tunnel. This tool tries to fetch an IPv6 address directly and shows the result.
Click "Run test" — takes a couple of seconds.
If no IPv6 address is found, there's no leak risk: either your provider or network has no IPv6, or your VPN is blocking IPv6 traffic entirely (which is the correct behavior).
If an IPv6 address is found while you're connected to a VPN, that's a potential leak — sites can get your real address and provider around the tunnel, even if your IPv4 address is hidden correctly.
If you're not connected to a VPN, detecting IPv6 is normal and expected.
Some VPN protocols and settings can fully block IPv6 to rule out this type of leak. Check with your VPN provider, or switch to 404 VPN.
How 404 VPN works →