Everything you need to know about Google Duo

The video-calling app by Google is encrypted so that no one – not even the search giant – can spy on you.

Meryl D'Souza August 17, 2016

What is Duo?

Google’s Duo is a video-calling app that is set to be a direct rival to Apple’s FaceTime. It is the first of two new mobile apps that Google, owned by Alphabet Inc., has planned for the summer. The second is a messaging app called Allo featuring a robotic assistant that will suggest automated responses to texts. Both were announced at Google’s I/O conference earlier this year. 

How does it work?

As you’d expect, Duo uses Wi-Fi or data to connect people. According to the company, the quality of calls adjust as the local network conditions change – which is corporate speak for stronger the connection, better the quality and vice versa. Having said that, the app is capable of switching seamlessly between Wi-Fi and mobile data to keep you connected, so you can potentially cut down on those data bills without disrupting a call.


This is where Google’s Duo has the advantage over Apple. While FaceTime – a stellar video calling up – limits its usage to iPhone users, Duo is compatible with Android and Apple.

User interface

Opening up the Duo app reveals just one button: video call. Tapping that loads your entire contact list for you to decide whom to call. This makes for a far cleaner interface than a Facebook Messenger or Skype app where you’re constantly hitting the call button accidentally. 

No conference calls

You probably guessed as much but as the name suggests, Duo is designed for one-to-one video calling exclusively on mobile devices, in contrast to Hangouts, Skype, Messenger and a plethora of other apps, which lets groups of people make video calls over mobile devices and computers.

Knock Knock

Here’s the most unique feature from Google’s Duo: the Knock Knock feature lets you "see live video of your caller before you answer". It does this by firing up the camera on the other end of the line. If you're initiating the call, you'll see a little notification that says your video is visible, which means the other person can see what you're doing right at that moment in real time. Don’t like it? No problem, the feature can be disabled.

It’s worth noting that Android users receiving a Duo call will see a Knock Knock video on the home screen by default. However, Apple devices will see a notification on top of the screen and will have to open the Duo app before seeing Knock Knock in action.

How is it different from Hangouts?

Yes, Google has Hangouts that allows for video or voice calling and has a bunch of other features, but Duo is supposedly specialised; it only exists for video calls.

There are two key differences between Duo and Hangouts though. Firstly, Duo reaches people through their phone numbers, not their Gmail. There’s no fuss about signing in. And secondly, Duo comes with end-to-end encryption (something that Facebook nor Skype has), which means your data can't be viewed from third parties or even Google itself.

'Encryption' has become a buzzword for the tech sector this year, after WhatsApp's move and the $14,000 Leo DiCaprio-endorsed Solarin phone. The trend is relatively young in the consumer market still, so expect to see more apps and devices using encryption as a selling point as the year continues.