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ISP IP appears while VPN is on? What to check

Find out why your ISP address may appear while a VPN is on, test for IPv6 or WebRTC leaks, and choose the right next step.

Kevin DoyleHardware tests Tests 4 min read

You turn on a VPN, but a website or diagnostic still seems to show your ISP address. That can point to a leak, but it can also be a normal address shown in the wrong place or a browser VPN that protects only browser traffic.

Use the VPN Leak Test while the VPN is connected. It checks whether your real IP address appears through IPv6 or WebRTC, then you can narrow down what to change.

Check the address with your VPN on

  1. Connect to your VPN and wait until its app or browser extension says it is connected. Note the selected VPN location.
  2. Open the VPN Leak Test in the browser and review the IP address and leak information it reports.
  3. If the test reports separate IPv4 and IPv6 information, compare each address with what your VPN provider says to expect. An address linked to your ISP or your actual location needs investigation.
  4. Run the test again after disconnecting the VPN. This gives you a useful comparison with the address your connection uses without the VPN.

For a fair comparison, keep the same browser and network for both runs. If you switch between Wi-Fi and mobile data, or connect to a different VPN location, the displayed address can change for reasons unrelated to a leak.

What the result means

The address matches the VPN location

The browser test sees an address associated with the VPN connection, which is the expected result. This does not prove that every app on your device uses the VPN, or that the VPN provider cannot see your activity. The test only checks for real IP exposure through IPv6 or WebRTC in the browser.

Your ISP address appears through IPv6

Your internet connection may have IPv6, while the VPN is routing only IPv4 traffic. In that case, the browser can reach a site over IPv6 outside the VPN tunnel. Check the VPN app for an IPv6 leak protection setting, or contact the provider for instructions. Do not disable IPv6 in your operating system unless the VPN provider recommends it for your setup.

Your ISP address appears through WebRTC

WebRTC is a browser feature used for real-time audio, video, and data connections. Depending on the browser and VPN configuration, it may reveal an address that does not match the VPN exit address. Check the VPN extension or app for WebRTC protection, and test again after changing one setting at a time.

The address looks unexpected, but no leak is reported

An address can be registered to a network company, data center, or VPN provider in a different place than the VPN server you chose. IP location databases are estimates, not precise location trackers. Check whether the address itself belongs to the VPN connection before treating a location mismatch as proof of a leak.

How to fix an unexpected ISP address

  1. Confirm the VPN is connected. Open the VPN app or extension and check its connection status. If it has disconnected or is reconnecting, wait for a stable connection before testing again.
  2. Check whether your VPN covers the browser. A VPN app usually routes device traffic, but a browser extension may protect only that browser. If the address appears in another app, check the full VPN app as well as the extension.
  3. Check for split tunneling. Split tunneling lets selected apps or websites bypass the VPN. Review the VPN app's settings and remove the browser from any bypass list if you want its traffic routed through the tunnel.
  4. Review IPv6 and WebRTC protection. Look for these options in the VPN app or extension. Change one setting, reconnect the VPN, and run the test again so you know which change affected the result.
  5. Check your device's VPN connection. On Windows 11, open Settings › Network & internet › VPN. On macOS, open System Settings › VPN. On iPhone, check Settings › VPN or Settings › General › VPN & Device Management. On Android, open Settings › Network & internet › VPN, though the exact labels can vary by manufacturer.
  6. Reconnect or update the VPN app. Disconnect, reconnect, and test once more. If the same address still appears, install available updates and ask the VPN provider which leak protection settings are supported for your operating system and browser.

What this test cannot tell you

A browser leak test is not a complete audit of your VPN. It does not test DNS leaks, traffic from other apps, or whether your ISP can see that you are connected to a VPN. Your ISP can generally see the connection to the VPN server even when the contents of traffic inside the tunnel are encrypted.

If you use a browser-only VPN extension, test the browser where the extension is active. The extension may not cover other browsers or programs. For more on how to interpret a reported leak and what to do next, see VPN leak detected? What to do next.

The test checks browser-visible network addresses. It does not change your VPN settings or certify that your connection is anonymous.

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