WebRTC Leak Test

How to test for a WebRTC leak

1. Turn your VPN on and connect to a server, then open or reload this page. The test runs by itself.
2. Check Your IP for normal browsing. With a VPN on, this should be the VPN server's address, not your home one.
3. Read the verdict. Leak found means WebRTC shows a public IP that is not your browsing IP, which is usually your real address.
4. For a baseline, run it once with the VPN off: both lines should then show your home IP, and the verdict says "No leak".
5. If there is a leak, follow the fixes below and press Test again.

What the results mean

• No leak: WebRTC only shows the same public IP websites already see. If that is the VPN's address, the VPN covers WebRTC too.
• Leak found: WebRTC shows a public IP that normal requests do not use. With a VPN on, that is almost always your real IP, which any website could read with a few lines of code.
• Local address (hidden): a random name ending in .local. Modern Chrome, Edge, Firefox and Safari hide your local IP this way unless a site has camera or microphone permission. This is safe.
• Local network IP: an address like 192.168.1.23. It is not your public IP and cannot be used to reach you, but it adds detail to a browser fingerprint.
• WebRTC is turned off: no addresses can leak, but video calls that run in the browser (Google Meet, Teams on the web, Discord in a browser) will not work.

What WebRTC is and why it can leak

WebRTC is the browser technology behind video calls, screen sharing and file transfer in the browser. To connect two people directly, the browser asks a STUN server: "what address do you see me coming from?". That question goes out over UDP, which some VPN apps do not route through the tunnel, or which the operating system sends out of the normal network card. The STUN server then sees your real public IP, and the web page can read the answer. No permission prompt is shown, which is why this leak surprised so many VPN users when it was found in 2015.

Most good VPN apps now block it, and browsers have reduced it, but it still happens with browser VPN extensions that only proxy web traffic, with split tunnelling, and with some free VPNs.

How to stop a WebRTC leak

• VPN app: turn on its leak protection or kill switch, turn off split tunnelling for the browser, and use the desktop app rather than only a browser extension.
• Chrome and Edge: there is no built-in switch. Install the official WebRTC Network Limiter extension from Google, or your VPN's extension with "WebRTC leak protection" turned on.
• Firefox: type about:config in the address bar, accept the warning, search media.peerconnection.enabled and set it to false. This turns WebRTC off completely.
• Brave: Settings > Privacy and security > WebRTC IP handling policy > "Disable non-proxied UDP".
• Safari: Safari already hides local IPs and does not leak through STUN in normal use; keep macOS or iOS up to date.

Run the test again after each change. Then check your IP address and use the DNS tools if you also want to confirm your DNS goes through the VPN.

Common problems and fixes

Leak found with the VPN on

Turn on the VPN's leak protection or kill switch, make sure the browser is not excluded by split tunnelling, and add WebRTC protection in the browser as described above. Test again.

Both lines show my home IP even with the VPN on

The VPN is not routing the browser at all, which is a bigger problem than WebRTC. Reconnect the VPN, try another server, and check what is my IP.

Video calls stopped working after the fix

Turning WebRTC off in Firefox or with an extension also blocks browser calls. Use the call app instead, or allow WebRTC only for the call site in the extension settings.

The test shows no public IP at all

Your network or firewall blocks STUN (common on work and school networks), or the browser limits WebRTC. Nothing can leak in that case.