Nearly a year after its launch, Google Duo now supports audio calling for all users worldwide. At the Google I/O conference last year, the company launched the minimalistic video-chat app for Android and iOS alongside its newest messaging app, Google Allo. Google pushed this new audio-calling feature to Duo users in Brazil last month, but it's only now making its way to all users across the globe. Justin Uberti, principal engineer at Google, announced the feature's availability today on Twitter.
According to a screenshot in Uberti's tweet, Duo users can choose to start an audio or video call by switching a toggle at the top of the app's interface. Duo launched as just a video-chatting app—and a basic one at that. It only allows one-to-one video calls and is only available for mobile devices, as it has no Web, Chrome, or desktop apps. You don't even need a Google account to use it—all you need is your phone number and your contact list to get in touch with someone using Duo.
Now that Duo isn't just a video-calling app, it could be better positioned to compete with the likes of WhatsApp and Facebook messenger, which both offer audio- and video-chat options. However, those other services also offer simple text messaging as well, and Google continues to scatter its messaging features across multiple apps. Allo is the text messaging portion that Duo would need to best compete with similar services, but Google intentionally launched both as separate apps last year.
Allo is a "smarter" version of Google Hangouts (which also has audio- and video-calling capabilities) that incorporates Google Assistant to provide answers to questions in the chat window and offer contextual information like flight times or nearby restaurants, depending on what you ask it for. It seems unlikely that Google would add a text messaging component to Duo in the future, but we can't rule it out, especially if enough Duo users ask for it as they did with this voice-calling feature.