Almost everything about your account or app experience can be taken care of with a visit to the app settings. In terms of usability, both apps work almost intuitively. No, WhatsApp has no personal computer app. Yes, calls can be made to available friends on desktops and laptops, making communication interchangeable between phones and PCs. This is its killer feature, allowing VoIP calls for free between Viber users, and for a price if calling a non-Viber number. This is especially important for OSes that don’t have chat history support. Yes, chat history can be backed up manually and emailed. Audio and video clips cannot be backed up, however. Yes-for Android, Windows Phone, and Nokia. This is its killer feature, allowing the users a poor man’s walkie-talkie feature. You can even switch a call from mobile to PC and back to mobile-if you’re feeling especially adventurous. But Viber takes the cake here because of its Windows and Mac apps, giving users the option to really have access to their app anywhere.

Of course, it would be nice if group calls were possible soon.Both Viber and WhatsApp are found on the most popular mobile operating systems on the market. I didn't use Skype for quite some time but speaking of the allround call experience Signal was the best of all those services. Either the bad quality or calls were cancelled continiously without any reason or because of 'bad internet connection' despite both of us had a stable connection and when trying another service it worked fine. I also used Viber and had problems pretty much with every call. The only problem I have somtimes is that I don't get a notification when someone calls me, at least not a proper one (whole screen pop-up) but got just a phone symbol in the notification bar. Sometimes we used non-Signal 'normal' calls using our provider when we were 3 people (no group-calls in Signal yet) and it was really bad compared to Signal calls. We were actually surprised how well we clould hear each other compared to WhatsApp. We played almost daily and always used Signal.

A friend and I used Signal calls while we played mobile games together for hours, so from our experience it was throughout very stable with good sound quality. I switched to Signal two months ago and deleted my WhatsApp account.

Privacy of viber vs whatsapp