What is WebRTC?
Understand browser calls, connection candidates and why a WebRTC address check differs from a public IP lookup or DNS test.
Website: https://zenshield.com/glossary/webrtc
Canonical URL: https://zenshield.com/glossary/webrtc
Page reviewed: 2026-09-12
WebRTC is browser technology for real-time audio, video and data connections. It helps a browser find a usable route to another participant. That process can expose connection addresses to the application running the call or test.
Why it appears in VPN checks
A normal IP lookup reports the address used for an HTTP request. WebRTC gathers possible routes, called ICE candidates. Those routes can differ from the one used to load a webpage, which is why a browser address check can be useful alongside an IP lookup.
An address can describe the local network, a public-facing route discovered through a STUN server, or a relay. These are different roles. Seeing a home-network address is not the same as seeing a second public internet address.
Interpret a browser test carefully
Use the WebRTC check and keep a public IP lookup open in another tab. Compare results on the same network. If a public address appears that you did not expect, check browser extensions and the VPN’s split-tunnelling settings before drawing a conclusion.
Some browsers substitute an mDNS hostname for a local address. Others restrict candidate gathering or rely on permissions. A test returning no numeric addresses can therefore mean that the browser limited the observation. It does not establish how another browser or another app would behave.
Should you turn it off?
Disabling WebRTC can break browser calls and other real-time features. First identify a specific problem and consult your VPN provider’s browser guidance. After changing a setting, retry both the address test and a call you actually use. A privacy change is more useful when you know what it changes and what it breaks.
WebRTC is separate from DNS. To investigate where domain lookups go, use the DNS test guidance.