What Is a WebRTC Leak and How to Prevent It ​

INFO

WebRTC (Web Real-Time Communication) is a browser technology that enables real-time audio, video, and peer-to-peer data connections.
A WebRTC leak occurs when, during the connection setup process (ICE candidate exchange), a browser or application unintentionally exposes your local or real public IP address.
This means that even if you are using a VPN or proxy, the target website or a third party could still see your real IP or LAN address — compromising your privacy and anonymity.

How a WebRTC Leak Works (Simplified Explanation)

1. When establishing a P2P connection, the browser uses a STUN/TURN server to obtain ICE candidates (potential connection addresses), which include:
   • host — the local (LAN) IP of your device
   • srflx — the public IP obtained via STUN
   • relay — the relay address provided through a TURN server
2. If the browser or a webpage script exposes or transmits host or srflx candidates, a third party could discover your real IP address (both local and public).
3. VPNs and proxies typically only route standard HTTP(S) traffic, but WebRTC STUN requests can bypass these routes, leaking your real IP.

To prevent WebRTC leaks in Chrome, you can install one of the following extensions:

• Official Google extension: WebRTC Network Limiter
• WebRTC Leak Prevent

To prevent WebRTC leaks in Firefox, open about:config and set the preference
media.peerconnection.enabled to false.
This completely disables WebRTC (note: doing so will also disable all WebRTC-based functionality).