23 October 2026 · 3 min read
What is WebRTC calling? How a browser tab makes a phone call
WebRTC is the technology that lets a browser tab make a phone call with no plugin and no app. What it is, why the audio can sound better than a desk phone, what it needs from your network, and where its limits are.
If you have joined a video meeting in a browser without installing anything, you have used WebRTC. It is the same technology that lets a browser dialer place a real phone call from a tab, and it is why calling software no longer needs a desk phone, a softphone install or a plugin.
What WebRTC is
WebRTC, short for Web Real-Time Communication, is an open standard for sending live audio, video and data between browsers and servers. It is built into Chrome, Edge, Firefox and Safari, so there is nothing to download. The browser asks once for permission to use the microphone, and from then on the tab can carry a call.
How a browser call reaches a phone
A phone is not a browser, so a call from a tab takes two steps. The browser sends the agent's voice over the internet to the calling provider's servers. Those servers hand the call to a carrier on the telephone network, which rings the mobile or landline at the other end. The person answering sees an ordinary call from your caller ID and has no way of telling it started in a browser.
Why the audio can beat a desk phone
WebRTC uses Opus, a modern audio codec that stays clear on modest connections and adapts when the network wobbles.
Echo cancellation and noise suppression are built into the browser.
Every WebRTC call is encrypted between the browser and the server. The standard makes encryption mandatory, not optional.
A wired USB headset plugged into the laptop avoids the worn cables and tired handsets of older desk phones.
The part of the call that travels over the traditional phone network sounds like any phone call. The improvement is in everything between the agent and the carrier.
What it needs from your network
Roughly 100 kilobits per second each way per call. That is tiny; most problems come from instability, not speed.
Low jitter and little packet loss. Wired Ethernet beats wifi on a busy floor, and a router shared with video streaming will hurt calls.
A firewall that lets the browser reach the provider's servers. Most office networks do; locked-down corporate ones sometimes need a rule.
A current browser. Keep Chrome or Edge up to date, and do not run calls in a window with dozens of heavy tabs open.
Our remote calling team setup guide goes further into headsets and connections.
The limits
WebRTC is only as good as the connection under it. If the internet drops, the call drops, and a laptop that goes to sleep ends a call the way a flat battery ends a mobile call. A stable line, a UPS on the router and power settings that keep laptops awake during a shift fix most of it.
WebRTC on ReachCalls
ReachCalls is built on WebRTC. Agents sign in from a browser tab and call with a local caller ID in the UK, Ireland, the US, Canada, Australia, France, New Zealand or Singapore, with nothing to install. Agents who prefer a separate window can use the Windows desktop app instead, and each seat can be signed in on two devices. Read more in what is a cloud dialer, or see the plans.
Questions people ask
Do I need to install anything to make WebRTC calls?
No. WebRTC is built into Chrome, Edge, Firefox and Safari. The browser asks for permission to use your microphone, and the tab can then make calls.
Are WebRTC calls secure?
WebRTC encrypts audio between the browser and the server, and the standard does not allow unencrypted media. The part of the call that crosses the public phone network is an ordinary phone call.
How much internet speed does a WebRTC call need?
Roughly 100 kilobits per second each way per call. Stability matters more than speed, so a wired connection usually sounds better than busy wifi.
