Comcast routers can now track motion in your home

Your Xfinity router can now tell when you walk across the living room.

Comcast launched a free update to its Xfinity Internet app that turns existing routers into motion detectors. The feature, called WiFi Motion, measures disruptions in radio signals between your gateway and connected devices to spot movement. It requires an XB7 gateway or newer, and Comcast told The Verge it spent three years refining the algorithms.

Why it matters: It gives millions of homes basic security tracking without requiring extra hardware or wall cameras. But turning ambient Wi-Fi signals into active home monitors raises immediate domestic privacy questions.

Here's the gist: the feature is opt-in, so it will not track anything until you manually enable it in the app using settings like Home Watch or Away Watch.

Physical motion sensors had a good run, but your router is officially coming for their job.