What is a WebRTC leak?

Quick answer

You can have a VPN running, see the VPN’s IP everywhere you look, and still be leaking your real IP address — through a browser feature called WebRTC. It’s one of the most common ways a VPN’s protection quietly fails. Here’s what’s happening.

What is WebRTC for?

WebRTC (Web Real-Time Communication) is a browser technology that lets sites do voice and video calls and peer-to-peer connections directly, without plugins — think browser-based video chat. To connect two peers efficiently, WebRTC needs to discover the real network addresses of your device.

Why does WebRTC leak your IP?

To establish those direct connections, WebRTC asks your device for its IP addresses and can share them with the website — including your real public IP, even when your traffic is routed through a VPN. Because this happens at the browser level, outside the VPN tunnel’s normal path, the VPN doesn’t mask it. The site sees the VPN IP for normal requests but can grab your true IP via WebRTC.

Why it matters

The entire point of a VPN is that sites see the VPN’s address, not yours. A WebRTC leak defeats that silently — you think you’re hidden, but any site running a few lines of JavaScript can read your actual IP. For anyone relying on a VPN for privacy, this is the leak to check first.

How to test for it

Turn your VPN on, then run our WebRTC Leak Test. It probes what WebRTC exposes and tells you whether your real IP (or only harmless local addresses) is visible. If your true public IP appears, you have a leak. Modern browsers increasingly mask local IPs with randomised .local names, which the test recognises as safe.

How to fix it

The fixes: enable your VPN’s built-in WebRTC/leak protection if it has one; disable or restrict WebRTC in your browser (see our guides for Chrome, Brave & Edge and Firefox); or use a browser extension that blocks WebRTC. Re-test afterwards to confirm the leak is sealed.