What is WebRTC?
WebRTC is a browser technology used for real-time audio, video and peer-to-peer communication. To establish those connections, the browser can gather ICE candidates that describe possible network paths.
What is a WebRTC leak?
In privacy testing, the concern is whether WebRTC exposes a public network address that differs from the public route you expected—for example, an address outside a VPN path. Modern browsers increasingly use mDNS and other protections, so seeing only local-looking candidates or no usable public candidate is normal on many systems.
Private candidates are not the same as public exposure
Local addresses such as private IPv4 ranges are not directly routable across the public internet. A WebRTC test is most interesting when it returns a public candidate that can be compared with the IP used for normal web traffic.
How to test a VPN
Connect the VPN first, confirm the public IP with the What Is My IP tool, then run WebRTC. If a public candidate appears and belongs to an unexpected ISP or network, investigate the browser and VPN configuration further.
Why an empty result is not a guarantee
Browsers can restrict candidate exposure without disabling WebRTC completely. This test shows what the current browser session exposes to this page; it is not a universal audit of every application on the device.