When comparing Viber vs Keybase, the Slant community recommends Keybase for most people. In the question“What is the best team chat software?” Keybase is ranked 31st while Viber is ranked 41st. The most important reason people chose Keybase is:
Completely end-to-end encrypted.
Ranked in these QuestionsQuestion Ranking
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 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 Android Wear support
Viber includes Android Wear support on Android 4.3 or higher and Viber 5.3 or higher.
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 Completely free
Viber uses data connection and the app is free.
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 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.
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 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 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 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 E2E encrypted
Completely end-to-end encrypted.
Pro Free static site hosting
Host a public static website for free. Sites are automatically viewable via keybase.pub if an index.html or index.md exist in your public files.
Pro Public teams
Teams can be public with open access or admin-approved access. Opt-in to list public teams.
Pro Private teams
Teams can be completely private (access granted via admin-approval only, not publicly listed).
Pro 250GB of free team file storage
250GB of free storage for encrypted files in a team.
Pro 250GB of free private file storage
250GB of free storage for privately-encrypted files.
Free (as in beer) and Open Source Software.
Pro Blockchain technology
Based on blockchain technology.
Pro Sigchain verification
View/verify the cryptographic signature history of any user.
Pro Shared private encrypted filesystem
Share files securely and privately with other users, a group of users, or a team.
Pro Private encrypted filesystem
Securely store personal files that only you can access.
Pro PGP/GPG support
Encrypt/decrypt any PGP message or file with minimal effort.
Pro Public key encryption
Supports public key encryption.
Pro Encrypted file sharing
Securely share files.
Pro Identity verification
Users can publish proofs of identity (PGP public key, Twitter, Facebook, etc).
Pro E2E encrypted team chat
Teams are E2E encrypted, unlike Slack and other services.
Pro Encrypted Git
Encrypted private or team Git repositories with automatic commit signatures.
Pro Public encrypted filesystem
For sharing files publicly.
Con Doesn't sync well
Sync awfully between Phone and PC clients.
Con No web client
You cannot login from the web to send and receive messages.
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 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.