Once users enter and verify their own phone numbers, they can invite other users to video calls by typing their phone numbers or by selecting them from their contacts lists. If a contact hasn’t tried Google Duo, users can send them a text message invite to download the app instead.
As users receive calls, the app’s Knock Knock feature will allow them to see live videos of their callers before they answer. All calls on Duo are end-to-end encrypted.
While on a call, Google said Duo will adjust the call quality automatically in response to “changing network conditions.” The app will also switch between WiFi and cellular data automatically without ending calls.