IPv6 Leak Test
This test detects whether your IPv6 traffic bypasses your VPN tunnel. Many VPNs only tunnel IPv4 traffic, allowing your real IPv6 address to leak and reveal your identity. We use dual-stack DNS probes to detect this.
What Is an IPv6 Leak?
An IPv6 leak occurs when your browser sends IPv6 traffic outside your VPN tunnel. Most VPN clients only route IPv4 packets through the encrypted tunnel, leaving IPv6 requests unprotected. If your ISP provides a dual-stack connection (both IPv4 and IPv6), websites can see your real IPv6 address even while your VPN is active.
How Does This IPv6 Leak Test Work?
We generate two sets of unique DNS subdomains: one that only responds with IPv4 (A) records and one that only responds with IPv6 (AAAA) records. By comparing which resolver IPs reach our DNS server for each set, we can detect if your IPv6 traffic takes a different path - indicating a leak.
How to Fix IPv6 Leaks
- Enable IPv6 leak protection in your VPN client.
- Switch to a VPN provider that supports full IPv6 tunneling.
- Disable IPv6 on your network adapter if your VPN cannot tunnel it.
- Enable your VPN’s kill switch to block all IPv6 traffic outside the tunnel.
For detailed VPN configuration steps, read our guide: How to Prevent DNS Leaks.
Related Tools & Guides
- DNS Leak Test - check if your DNS queries leak outside your VPN tunnel.
- WebRTC Leak Test - detect if WebRTC exposes your real IP address.
- IP Lookup - check your public IPv4 and IPv6 addresses plus geolocation data.
Frequently Asked Questions
Does IPv6 leak testing work without IPv6 connectivity?
Yes. If your ISP does not provide IPv6, the test will report “No IPv6 Connectivity” and confirm that an IPv6 leak is impossible on your current network. The test is still useful because your connectivity may change across networks.
Why do I have IPv6 connectivity but no leak?
This means your VPN client is correctly tunneling both IPv4 and IPv6 traffic. Both protocol stacks exit through your VPN server, and your real address stays hidden. This is the ideal result.
Should I disable IPv6 entirely?
It depends on your VPN. If your VPN fully supports IPv6 tunneling, keep it enabled for better compatibility with modern websites. If your VPN only tunnels IPv4, disabling IPv6 at the adapter level is the safest option to prevent leaks.