Difference between WhatsApp Messenger and Viber

1. WhatsApp Messenger :
WhatsApp Messenger, or simply WhatsApp, is a cross-platform messaging service owned by Facebook, Inc. It allows users to send text messages, voice messages, make voice calls, video calls, share images, documents, user locations, and other media.

2. Viber :
Rakuten Viber, or simply Viber, is a cross-platform voice over IP and instant messaging software application. It allows users to exchange media such as images, videos, free and secure calls and messages to anyone, anywhere.

Difference between WhatsApp Messenger and Viber :

WhatsApp	Viber
It is owned by Facebook, Inc.	It is also owned by Japanese multinational company Rakuten.
It was launched on 3rd May, 2009.	It was launched on 2nd December, 2019.
Whatsapp allows to personalize the appearance of the app like choosing a different theme or colors.	Viber requires a Gmail login to get started.
Whatsapp is add free.	Viber is not add free.
There is no option such that an image which automatically disappears once the person has seen it.	In Viber you can send an image which can disappear once the person has seen it.
In whatsapp there is no facebook sign in option.	In Viber there is a facebook sign in option.
In whatsapp you can set notifications to snooze mode if you don’t want to be disturbed during a specific time frame.	In Viber you cannot do so.
In whatsapp maximum of 256 persons can be there in a group.	In Viber maximum of 200 persons can be there in a group.
Whatsapp messenger has no cloud sync.	Viber has cloud sync.