Check if your IPv6 address slips past your VPN

Some VPN configurations protect IPv4 but leave a public IPv6 route open. This live browser check shows whether a public IPv6 address is visible on this connection and helps you compare the result before and after connecting.

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IPv6 leak test showing address exposure through a VPN

Checking for IPv6 addresses...

Reading your results

No IPv6 found: Your connection is IPv4-only, or IPv6 is disabled. No IPv6 leak is possible from this device.
Link-local only: You have a private link-local address (fe80::). These are not routable on the internet and cannot identify you. Safe.
Public IPv6 found: You have a real, routable IPv6 address. If your VPN does not tunnel IPv6, websites can see this and use it to identify your ISP and location.

What this browser test can tell you

The test gathers IP candidates exposed to this browser and separates public IPv6 addresses from link-local addresses. A public result matters because an internet site can route to it. A link-local address starts with a private range such as fe80:: and works only on your local network.

A positive result is actionable

If the same public IPv6 address appears before and after the VPN connects, the browser still has a path outside that tunnel. Save the result, check the VPN's IPv6 setting, and test again after making one change.

A clean result has limits

No address found means this browser did not expose public IPv6 during this run. It does not inspect every app, router rule, or future network. Repeat the check after changing Wi-Fi, mobile networks, or VPN software.

For the protocol background—why dual-stack networks exist, how traffic can bypass a tunnel, and how IPv6 differs from DNS and WebRTC—read the separate IPv6 leak explanation.

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Run a useful before-and-after check

One result by itself lacks a baseline. Compare the same browser on the same network with the VPN off and on:

Disconnect the VPN, run the test, and note whether a public IPv6 address appears.
Connect the VPN and wait until its status is stable.
Run the test again in the same tab.
Compare the address type and value, not just the green or amber message.

How to read the comparison

If the baseline has public IPv6 and the connected result does not, the VPN is blocking that path. If both show the same public address, investigate a leak. If neither run finds IPv6, this network cannot exercise the IPv6 path, so repeat on another network before drawing a broad conclusion.

How to fix an IPv6 leak

There are two approaches: disable IPv6 on your device so no IPv6 traffic can leave at all, or use a VPN that explicitly tunnels IPv6 traffic alongside IPv4. Disabling IPv6 is the more reliable fix for most users because it removes the issue at the source regardless of your VPN client's implementation.

Windows

Open Network Connections (search for "ncpa.cpl" in the Start menu). Right-click your network adapter and select Properties. Uncheck "Internet Protocol Version 6 (TCP/IPv6)" and click OK. Repeat for any other active network adapters (Wi-Fi and Ethernet).

For a more targeted fix, open PowerShell as Administrator and run: Disable-NetAdapterBinding -Name "*" -ComponentID ms_tcpip6

macOS

Go to System Settings, then Network. Select your active network interface (Wi-Fi or Ethernet) and click Details. Go to the TCP/IP tab. Change "Configure IPv6" to "Link-local only". Click OK and repeat for all active interfaces.

Link-local only keeps IPv6 available within your local network but prevents your device from using public IPv6 addresses on the internet.

Linux

To disable IPv6 system-wide, add the following lines to /etc/sysctl.conf:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Then run sudo sysctl -p to apply. Verify with ip -6 addr, which should return no addresses.

Android and iOS

Mobile operating systems do not expose a simple toggle for disabling IPv6. On Android, the most reliable fix is using a VPN app that handles IPv6 explicitly. On iOS, Safari's WebRTC behavior already limits IP exposure, but apps outside the browser may still use IPv6.

On mobile, your best option is to verify that your VPN app tunnels IPv6 or explicitly blocks it, then run this test with the VPN connected to confirm.

After applying a fix

Return to the test at the top of this page and run it again. If you disabled IPv6 correctly, the test should show "No IPv6 address detected." If a public IPv6 address still appears, check whether you have multiple network interfaces or whether your router is re-enabling IPv6.

Related tools and guides

Full VPN Leak Test

IP address, WebRTC, and IPv6 in one combined test.

WebRTC Leak Test

Check if your browser exposes your real IP through WebRTC.

IP Address Lookup

Full details on your current public IP, location, and ISP.

IPv6 Leaks and VPNs

Full explanation of IPv6 leaks and how to prevent them.

Public vs Private IP

The difference between your public and local IP addresses.

Testing Your VPN

A step-by-step process for verifying your VPN works correctly.

Frequently asked questions

Do I have an IPv6 address?

Run the test above to find out. IPv6 assignment varies by country and ISP. In the United States, Germany, Belgium, and several other countries, dual-stack connections (both IPv4 and IPv6) are common. In other countries, IPv4-only connections are still the norm. Mobile connections are increasingly IPv6-only or dual-stack. The test tells you exactly what applies to your current connection.

If I have no IPv6 address, am I fully protected from this type of leak?

Yes. An IPv6 leak requires an active public IPv6 address to leak. If your connection is IPv4-only, or if IPv6 is disabled on your device, no IPv6 traffic can leave your device and no leak is possible. The test result 'No IPv6 address detected' means you are not at risk from this specific issue on this device.

How does this test detect my IPv6 address without contacting a server?

This test uses your browser's WebRTC API to collect ICE (Interactive Connectivity Establishment) candidates. When the browser prepares for a peer-to-peer connection, it discovers all available network interfaces on your device, including IPv6 addresses. Public IPv6 addresses found this way are the same ones that would be visible to any website that requests a WebRTC connection from your browser. No data is sent to our servers.

What is a link-local IPv6 address and is it a problem?

Link-local addresses start with fe80 and are used only within your local network segment. They are automatically assigned by your OS for communication between devices on the same network (like your computer and your router). Link-local addresses are not routable on the internet: external websites cannot use them to contact you or identify you. Seeing a link-local address in the results is normal and harmless.

Will disabling IPv6 cause problems with my internet or apps?

For most home users, disabling IPv6 causes no noticeable issues. Nearly all websites and services work over IPv4, and your device and browser fall back automatically. You may see slightly slower loading on sites that prefer IPv6, since the connection falls back to IPv4. In rare cases, certain enterprise or university networks require IPv6 for internal routing. If you are on a managed network, check with your IT team before disabling it.

I disabled IPv6 but the test still shows an IPv6 address. Why?

Your device may have multiple network interfaces, and the change may only have applied to one of them. On Windows, check all adapters in Network Connections. On macOS, apply the change to both Wi-Fi and Ethernet. On Linux, confirm the sysctl changes applied to all interfaces. Also check whether your browser cached previous results. After making changes, run the test in a fresh tab.

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