IPv6 leak test

Many VPNs only tunnel IPv4. If your network has IPv6 and the VPN doesn't handle it, your real IPv6 address can leak.

IPv4
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IPv6
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How to use the ipv6 leak test

  1. Open the page — IPv4 and IPv6 are detected automatically.
  2. If an IPv6 address shows while your VPN only tunnels IPv4, that's a leak.
  3. Disable IPv6 or switch to a VPN that handles it.

Why IPv6 leaks happen

Many VPNs only route IPv4 traffic. If your network also has IPv6 and the VPN doesn't tunnel or block it, websites can reach you over IPv6 and see your real address — completely bypassing the tunnel. A proper VPN either routes IPv6 through the tunnel or disables it while connected.

Code & API examples

Use this from the command line or your code.

IPv6 (curl)
curl -6 https://api6.ipify.org
IPv4 (curl)
curl -4 https://api.ipify.org

See all endpoints at /api/tools/.

Frequently asked questions

When your VPN only routes IPv4 but your connection also has IPv6, sites can still see your real IPv6 address — a leak that bypasses the tunnel entirely.

If your VPN doesn't fully support IPv6, disabling it removes the leak. A better fix is a VPN that tunnels or blocks IPv6 properly.
Related tools
Is my VPN working? What is my IP address? DNS leak test
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