When comparing WeChat vs Viber, the Slant community recommends Viber for most people. In the question“What are the best messaging apps for Android?” Viber is ranked 8th while WeChat is ranked 44th. The most important reason people chose Viber is:
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.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Friends can be added by scanning a QR code
WeChat generates a QR code for each user that other can be scanned to add them as a friend.
Pro Can be used as a Walkie Talkie
WeChat has push-to-talk functionality that can be used both one-on-one and in groups.
Pro Large collection of animated stickers
Pro Easy to send voice messages
Users can record a voice message from within the app to then send it to a recipient, who can then play the message from within the app. It is all self contained.
Pro Enables meeting new people
WeChat has a feature that pairs random people for a conversation. It is activated by shaking the phone (requires location sharing to be enabled) and will present a list of people who are doing the same and how far away from you they are.
Another feature for meeting new people is the Friend Radar that will display people in your vicinity that can then be added to your contacts list.
Finally, there is the People Nearby feature which allows you to send and receive greetings from people in your vicinity.
Pro Moments social network is seamlessly incorporated
Pro Flexible creation of chat groups
You can create chat groups for up to 500 people.
Pro Filters for photos
WeChat includes a collections of filters that can be applied to photos to change how they look.
Pro Desktop apps allow texting, calling and enables transferring calls between devices
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.
Pro Supports voice calls
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.
Pro Completely free
Viber uses data connection and the app is free.
Pro Clean interface
The interface is simple, functional and intuitive.
Pro See who of your contacts is using Viber quickly
Viber is tied to your phone number so it can quickly see who else in your contacts list is using the application.
Pro Android Wear support
Viber includes Android Wear support on Android 4.3 or higher and Viber 5.3 or higher.
Pro Same protocol as used in Signal
Viber's protocol uses the same concepts of the "double ratchet" protocol used in Open Whisper Systems Signal application.
Pro Public chats
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.
Pro Supports video calling over WiFi and data.
Can call friends using voice or video options.
Pro Combines cellular and data messaging
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.
Pro Keys only on device
Starting with Viber 6.0 the encryption keys are stored only on the clients themselves, not even Viber itself has access to them.
Pro No need to create an account or add contacts
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.
Pro Supports 200 person group chat
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.
Pro Insight and well documented encryption
Viber has made a documentation available, explaining in great details their encryption system and giving good insight on how it works.
Cons
Con Notifications get muted after inactivity
New message notifications stop getting pushed if the application isn't opened for some extended period of time (seems to be around a week or so)
Con WeChat complies with China's requirements to hand over data
Con Conversations and chat groups aren't ported to new devices
Messages are stored on each device, so shifting to a new device means losing all the previous conversations, as well as an inability to post in previous chat groups until someone else posts there and you're alerted of a new message.
Con User base outside of China is comparatively small
While WeChat has over 400 million users the majority of them are in China. Adoption in other markets has been slow.
Con The company evades U. S. tax
The company uses the common practice of tax haven addresses in order to avoid paying US taxes despite being registered in Delaware.
Con Proprietary Software
Not Open Source.
Con No web client
You cannot login from the web to send and receive messages.
Con Constantly on
Need apps like Greenify to stop it from being constantly on and active, even if you don't use it.
Con Constant reminders of messages
If you don't check your messages (say your in a group chat and simply don't check all of them), it will flood your notifications.
Con Doesn't sync well
Sync awfully between Phone and PC clients.
