How to Check if Your VPN Is Leaking Your IP or DNS (Step by Step)

A VPN only protects you if all of your traffic goes through it. When some of it slips around the tunnel, that is called a leak. Leaks are usually caused by a setting, not by a broken VPN, and they take a few minutes to find and fix.

The three leaks to test for

IP leak: websites can see your real IP address while the VPN is on.
DNS leak: your device still asks your internet provider's DNS servers which addresses to visit, so the provider can see the names of the sites you open.
WebRTC leak: a browser feature used for video calls reveals your real IP address to websites.

Step 1: write down your real IP address

With the VPN off, open an IP check website (for example ipleak.net) and note the IP address and the internet provider shown. This is what a leak would reveal.

Step 2: connect the VPN and test again

Connect the VPN to any server.
Refresh the same page.
The IP address and provider should now belong to the VPN, not to your home connection.

If you still see your real IP address, you have an IP leak. The most common causes are a VPN app that did not finish connecting, or a second network adapter (for example Wi-Fi and Ethernet at the same time) that the VPN does not cover.

Step 3: run a DNS leak test

Most leak-test sites have an "extended" DNS test. Run it with the VPN on and look at the list of DNS servers.

Pass: the servers belong to your VPN provider or a DNS service it uses.
Leak: you see your home internet provider's name in the list.

Step 4: check WebRTC in your browser

The same test pages show WebRTC results. If a WebRTC section displays your real public IP address while the VPN is connected, your browser is leaking it.

How to fix each leak

Fixing an IP leak

Reconnect and wait until the app clearly says "Connected".
Turn on the kill switch, so traffic stops if the VPN drops. Our guide to the VPN kill switch explains how to test it.
Check IPv6. If your provider gives you an IPv6 address and the VPN does not support IPv6, traffic can leak through it. Enable the VPN's IPv6 leak protection, or turn off IPv6 on your network adapter.

Fixing a DNS leak

Enable DNS leak protection (sometimes called "use VPN DNS only") in the VPN app.
Remove any custom DNS you set manually in your network settings or router, because it can override the VPN's DNS.
On Windows, a feature called smart multi-homed name resolution can send DNS queries to every adapter at once. Good VPN apps block this automatically; if yours does not, update the app.

Fixing a WebRTC leak

Use the browser extension your VPN provider offers, which usually blocks WebRTC leaks.
In Firefox, WebRTC can be limited in advanced settings. In Chromium browsers, a reputable WebRTC-control extension does the same job.

Test again after every fix

Repeat steps 2 to 4 after each change. When the IP address, DNS servers and WebRTC results all show the VPN, you are protected.

When to contact the provider

If leaks remain after the fixes above, contact your VPN provider's support with your test results. If you bought your VPN from us, start a chat with the button below this page and we will help you work through it.

Looking for a VPN with leak protection and a kill switch built in? See Nova VPN Premium.