# 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](https://zenshield.com/tools/webrtc-leak-test) and keep a [public IP lookup](https://zenshield.com/tools/what-is-my-ip) 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](https://zenshield.com/tools/dns-leak-test).

## Sources
- https://developer.mozilla.org/en-US/docs/Web/API/WebRTC_API
- https://developer.mozilla.org/en-US/docs/Web/API/RTCIceCandidate/type