When comparing WhatsApp vs Signal Private Messenger, the Slant community recommends Signal Private Messenger for most people. In the question“What are the best cross-platform & encrypted messaging apps?” Signal Private Messenger is ranked 3rd while WhatsApp is ranked 6th. The most important reason people chose Signal Private Messenger is:
Backed by people nut about privacy, including - Edward Snowden, Whistleblower and privacy advocate - Laura Poitras, Oscar winning filmmaker and journalist - Bruce Schneier, internationally renowned security technologist - Matt Green, Cryptographer, Johns Hopkins University
Ranked in these QuestionsQuestion Ranking
Pro Straightforward interface
The interface is very simple, fast and easy to use. You can start using it as soon as the app has been downloaded - it does not require setting anything up or registering. You can communicate with anyone in your contacts list that also uses WhatsApp. Includes useful features like seeing when a contact is currently available or typing.
Pro Effortlessly builds your contacts by using your phone number as identification
WhatsApp will automatically find all of your contacts currently using Whatsapp and add them to your contacts. This makes it really easy to setup and given that it's the most popular messaging app it's likely that a lot of your contacts are already using it.
Pro Widely used
WhatsApp reported 800 million users in April, 2015. Your friends are most likely already using WhatsApp, so it's easy to get setup. Also it's the overall highest rated messaging app on the play store.
Pro Message mirroring on web app
WhatsApp can be used from the desktop via Chrome, Firefox and Opera browsers. Accessing it requires using the Android app to scan the QR code that's presented on web.whatsapp.com.
Pro One-on-one texts can be encrypted
WhatsApp has implemented end to end encryption for messages sent on it's service. Even WhatsApp has no way to read a users messages.
Pro Truly open and secure, comes from the Open Whisper Systems Team
Backed by people nut about privacy, including
- Edward Snowden, Whistleblower and privacy advocate
- Laura Poitras, Oscar winning filmmaker and journalist
- Bruce Schneier, internationally renowned security technologist
- Matt Green, Cryptographer, Johns Hopkins University
Pro Encrypted voice calling
Unlike many other apps, signal provides not only text messaging but also live encrypted voice calling.
Pro Free as in both free beer and freedom, not as in "The customer is the product"
Pay Nothing - The development team is supported by community donations and grants. There are no advertisements, and it doesn't cost anything to use.
Con Single device
You cannot use the same WhatsApp account on multiple devices (e.g. a tablet, a PC and a cellphone). The account is tied to the device with the specific cellphone number. Chat history is deleted when you sign in to a new account, unless you have created a backup.
Con Hard to migrate history cross platform
Migrating your chat history from Android to iOS or the other way around is not so simple. In some cases it requires a 3rd party app and in some the only way is to migrate specific chats one by one.
Con Shares meta data with Facebook
WhatsApp shares your messaging meta data with Facebook if you do not opt-out in the settings. If you use the same phone number for WhatsApp and Facebook, the profiles can easily be linked.
Con No cloud sync
Messages are not stored on WhatsApp server for privacy and security reasons.
Con Limitation on shareable file sizes
WhatsApp now allows users to share files of any type, but there is still a size limit.
Not open source.
Con Tied to carrier phone number
WhatsApp cannot be used by people without a smart phone with an active cell plan. If your phone is lost or damaged, or if your phone number changes, you cannot get messages sent by friends without them updating your phone number. You cannot send message to them until you are able to get SMS messages at your phone number.
Con Web interface uses message mirroring
To use your computer to send messages your phone must be on with a consistent data connection.
Con Requires phone number to register
Con Centralized architecture
Signal's server architecture has been partially decentralized since December 2013, when it was announced that the messaging protocol that is used in Signal had successfully been integrated into the Android-based open-source operating system CyanogenMod. As of CyanogenMod 11.0, the client logic is contained in a system app called WhisperPush. According to Open Whisper Systems, "the Cyanogen team runs their own Signal messaging server for WhisperPush clients, which federates with Open Whisper Systems' Signal server, so that both clients can exchange messages with each-other seamlessly".
The WhisperPush source code is available under the GPLv3 license. In January 2016, however, the CyanogenMod team announced that they will be discontinuing WhisperPush on February 1, and recommended that its users switch to Signal. After this, Signal's server architecture will be entirely centralized.
Con Code being used in Whatsapp and other parties undermines trust
It's unlikely FB would add encryption it does not have access to.