What Is a WebRTC Leak?

A WebRTC concern arises when browser connection candidates reveal network information you did not expect a page to observe.

How it works

WebRTC supports real-time voice, video, and data features. Browsers collect ICE candidates to establish connections. Modern browsers often use mDNS hostnames or privacy controls that prevent direct local-IP exposure. Seeing a candidate is not proof of a public-IP leak; the candidate type, browser behavior, and whether it is routable all matter.

ICE candidates can include relay, server-reflexive, host, or mDNS information. A relay candidate may identify only a relay, while an mDNS candidate is deliberately designed to conceal a local address. The labels and context matter more than a dramatic interpretation of any one string.

A useful test reports what the browser exposes and leaves the decision to the user. If you use video meetings, test changes carefully because blocking WebRTC wholesale can affect calls and screen sharing.

Practical guidance

• Run a browser-side WebRTC candidate test rather than relying on a server-side guess.
• Review browser privacy settings and VPN documentation if candidates differ from your expectation.
• Keep your browser updated because privacy behavior changes over time.

Common question

Should I disable WebRTC? Usually not as a first step. It can break calls and conferencing. Assess the actual candidate result and your privacy need first.