WebRTC (Web Real-Time Communication) is a technology for real-time voice calls, video calls, and data sharing inside a web browser, with no plugin or app installation required. Google released the implementation in 2011, and the W3C has since standardized it as a Recommendation, while the underlying communication protocols are specified by the IETF. As of 2026, Chrome, Firefox, Safari, and Edge all support it out of the box.
The defining feature is that a call needs nothing but a browser. Where VoIP calling normally assumes a dedicated app, WebRTC lets someone join a call simply by opening a URL. Google Meet is built on the technology, which is why a browser alone is enough to enter a video meeting. The browser does ask for permission before it uses the microphone and camera, so a first call always includes a prompt to accept.
How the connection is formed depends on how many people are talking. A one-to-one call uses a direct peer-to-peer (P2P) connection between the two devices, and the short path helps keep latency low. Group calls generally run through a media server (an SFU) that receives the audio and video from each participant and redistributes it. Devices sitting behind home or office routers cannot always reach each other directly either, and in that case the media travels through a relay server. Encryption is mandatory: protection by SRTP (Secure Real-time Transport Protocol) and DTLS (Datagram Transport Layer Security) is always in effect.
Corporate telephone systems use WebRTC as well. Browser clients for cloud PBX services and the "click-to-call" buttons embedded in websites, which let a visitor reach a company with a single click, are the familiar examples. See also the basics of VoIP.
One point deserves care: a WebRTC call is not the same thing as a call placed through the telephone number system. WebRTC on its own is not assigned a phone number, and reaching the telephone network requires a carrier gateway in between, so it cannot be used for emergency calls such as 110 or 119. And because a P2P connection exchanges data directly with the other device, your IP address can become visible to the person on the other end, which is worth keeping in mind when that person is a stranger.