If you are confused as to which VoIP application to use on your mobile device, both are very good options. They can be used for making free audio as well as video calls using the Internet or your phone data. Skype has been there for a longer time and has a much bigger user base, whereas Viber is comparatively new, but is still doing fine and catching up quickly. Both the applications are cross platform and can be used on the desktop as well as mobile phones of different operating systems.
Both the apps offer free messaging as well as calling features. Both the apps will only allow you to make free calls to those who also have the app downloaded on their phone, so it is better to select the one that most of your contacts have. Of course, you can also contact other landlines and mobiles that don’t have the app, but you have to pay for it, albeit nominally.
It is much cheaper to make calls using VoIP apps rather than the conventional telecom carrier. However, to make good quality calls, you must have a good connection, with 3G or even 4G if you have a data plan. Your Wi-Fi connection must also have a good speed. As far as the amount of data used is concerned, Viber is more economic, whereas Skype uses more data, but the quality of call clarity offered by Skype is surely better.
Both the applications are simple to install on your phone. The functionalities vary a bit, with Skype requiring username, email add and password during the installation process. On the other hand, Viber only needs the phone number. You will also have to log in to Skype very often, whereas there are no login problems in Viber, as it launches whenever you want, after installation.
In order to add contacts to Skype, you have to know the email address of your contacts or friends. On the other hand, Viber makes it very easy to add contacts, as it makes use of the contacts on your phone book and automatically adds these to the Viber contact list.
Viber as well as Skype allows users to make calls to landlines and other mobile numbers that are not on the contact list or those that do not have the application. However, a nominal fee is charged for such calls by both the apps. Skype allows you to make calls to a wider range of people, as it has a larger user base. You can call those having Skype and also those who hold Hotmail or MSN accounts, since Microsoft has taken over Skype.
Both Viber and Skype are very popular, but it depends on which app most of your friends and contacts are having. In addition, as far as the quality of calls is concerned, Skype is superior with better codecs compared to Viber. However, it also consumes more data than Viber. The best way to resolve the dilemma would be to install both the apps and use them for some time, try out the features, check out the quality of the calls and then make an informed decision. However, Viber seems better suited for mobile phones, whereas Skype is more suitable for the desktop.