WebRTC is a browser technology used for video calls, voice chats, screen sharing, and peer-to-peer communication. To connect two browsers, it may gather network candidates. These candidates can include local network addresses, relay addresses, or public addresses discovered through a STUN server.

A WebRTC leak is not simply "WebRTC found a public IP." If you are not using a VPN, the public IP seen through WebRTC may be the same public IP the website already sees. That is normal internet behavior. A more concerning result is when WebRTC exposes an address that differs from the expected VPN or proxy exit address and appears to reveal another network path.

How to test correctly

First run the test without a VPN and record the normal public IP. Then enable the VPN or proxy and reload the page. Compare the page-visible IP with the WebRTC public candidate. If they match, the result is not proof of a VPN leak. If the WebRTC candidate is different from the VPN exit IP and resembles your real network, treat it as a possible leak and investigate.

Browser behavior

Modern browsers have reduced many older WebRTC leak patterns. Some browsers hide local IPs behind mDNS names. Others may block public candidates until permission or policy allows them. Extensions, enterprise policies, VPN apps, and privacy modes can all change the result.

Fix options

Use a browser with WebRTC leak protection, enable your VPN app's leak protection feature, or restrict WebRTC in browser settings where available. If you need WebRTC for calls, test after changing settings to make sure video and audio apps still work.

Limitations

This page can show visible candidates and compare them with the public IP observed by the site. It cannot know your private intention, your VPN provider's internal routing, or whether every app on your device is protected.