Skype vs Viber

There's a good chance that whoever you're trying to reach has Skype already set up and familiar with it, avoiding the hassle of installing and getting to know new software.

You can show your whole desktop, a select part of the screen or a specific window over Skype.

There's software for Windows, Mac & Linux and apps are available on iPhone, Android, and Windows Phone.

You can hold video calls with up to 10 people.

A stripped down, minimalist version of Skype is available for Linux.

Skype allows you to send any files (MP3s, images, text, etc.) by simply dragging and dropping then in the chat window making it simple to share things with colleagues.

Starting at $5/mo you can get a Skype number.

With Skype Credit bought or a subscription, you can send SMS and make direct calls.

Viber has native apps for both Windows and Mac that allow you to send and receive messages from your desktop. You can also use the desktop to make and receive calls. Synchronizes between all devices you are using Viber on. Allows transferring calls between devices.

Viber has really well implemented voice tech. It has comparable quality to Skype and you can even tranfer calls from your phone to your desktop seamlessly.

Viber uses data connection and the app is free.

The interface is simple, functional and intuitive.

Viber is tied to your phone number so it can quickly see who else in your contacts list is using the application.

Viber includes Android Wear support on Android 4.3 or higher and Viber 5.3 or higher.

Viber's protocol uses the same concepts of the "double ratchet" protocol used in Open Whisper Systems Signal application.

It's possible to be a fly on the wall on other group or one-to-one chats that have been opened up to the public. These public chats are often promotional chats with celebrities.

Can call friends using voice or video options.

This has an advantage in that if you text someone who uses Viber it will be free, if not it will just revert to SMS. This means you can replace your standard messaging app with Viber as well.

Starting with Viber 6.0 the encryption keys are stored only on the clients themselves, not even Viber itself has access to them.

One of the best things about Viber is how it handles setup and sending messages. Viber uses your existing number as your ID, so you don't need to create a separate Viber account.

Viber allows creating groups of up to 200 people on the Android version of Viber. It also has a cool "smart notifications" feature to prevent being overwhelmed with notifications if a lot of people are active in a chat group.

Viber has made a documentation available, explaining in great details their encryption system and giving good insight on how it works.