A few requirements for full functionality:
Viber for iPhoneiPhone 4 and later
iOS 7.0 and above
2.3.6 and above
Viber for Android
Viber for Nokia
Supports free messaging service only.
Stickers and emoticons are not available.
To find out if your device is supported, please check the Opera Mobile Store
Windows Phone 8
Viber for Windows Phone
Minimum 512 MB RAM is required.
Delay in call notifications may occur. Issue resolution is in progress in cooperation with Microsoft.
OS5, OS6, OS7
Viber for Blackberry
OS5 users running platform 6.x.x. must have OS 188.8.131.528 or below for voice calls.
OS6 devices support free messaging service only, except in CDMA devices.
Only full-touch devices running BlackBerry version 10.2.1 and later are supported
*Note: Blackberry store might disable some devices that do meet the above requirements.
(Viber for Desktop can be installed only after the most recent version of the application has been installed on a mobile device)
Viber for Desktop*
Windows: 8, XP SP3, Vista
Mac: OSX 10.7 and above
Linux: 64 bit
*Minimum hardware requirements:
CPU: Dual core processor
Memory: 1GB RAM, 1MB disk space
Microphone and speakers for voice calls and webcam for video calls
AD2P compatible Bluetooth receiver for BT devices