According to a report today from 9to5Google, a web client for Duo will be launched "in the coming weeks." When it happens, Duo will join desktop-compatible ranks of
Android Messages and dearly departed Allo, expanding the reach of the service away from phones and Smart Displays.
Functionality at launch remains a question. 9to5Google speculates that the app's trademark features like "knock knock" (which provides a live feed of the caller before you answer) and sending/leaving video messages are likely to be included.
Duo connects to your account using both your phone number and Google credentials, making it possible one could sign into the desktop client more conveniently (and sanely) than the existing QR code system used by Allo and Messages. The apparently short schedule and the lack of a QR system in recent Duo teardowns also support the idea that a different mechanism may be used.
Although Allo wasn't successful, Google's Duo Video Calling service has seen more widespread adoption, recently crossing 1 billion downloads on the Play Store as it continues to add features like group calling and low-light mode. A web client represents a significant ongoing investment into the platform, and spreading functionality to desktop browsers and Chromebooks will only increase consumer use.