As a general rule of thumb, chat apps that utilize end-to-end 256-bit AES, enterprise-level encryption are considered the holy grail when it comes to privacy. With end-to-end encryption, each message you send is scrambled and encoded directly on your phone, and only decoded by intended recipient after delivery. This process of encryption is important as it allows only you and the receiver to read your conversation, thus stopping malicious actors from reading the content of your chats, even in the unfortunate case they manage to intercept them while the data is in-transit.
Most Android devices come with a semi-encrypted solution in the default Google Messages SMS app, but there are better solutions out there, both for SMS/MMS and for internet-based messaging. We have selected some of the best options for you here.
What is encryption?
Encryption occurs when the message's code is processed by an encryption algorithm (a block of instructions), which should be AES compliant (Advanced Encryption Standard). AES is also known by its original name Rijndael, and was initially established by the U.S. National Institute of Standards and Technology (NIST) in 2001. The 256-bit refers to the length of the key used to encrypt the information and is virtually unbreakable by brute force when considering current computing power. Because of this, it is considered the strongest encryption standard to-date.
There are various encryption standards that are beyond the scope of this post, and you can check out our end-to-end encryption explainer for more details. Since end-to-end encryption offers the best protection from prying eyes. All of the messages in our list support end-to-end encryption.
Encrypted messaging on Android and iOS
Both the Android and iOS ecosystems offer many security and privacy-focused mobile apps that allow us to send messages without worrying whether malicious actors — or government agencies — will be able to read the content. Unfortunately, some of the most popular messaging apps, such as Facebook Messenger, do not offer end-to-end encryption by default (outside secret chats), which means that hackers and the company itself would be able to read your messages if they're able to intercept them.
Additionally, while the Google Messages app does offer end-to-end encryption when sending messages via RCS, it still falls short since that coveted encryption only occurs during one-on-one messages (not group chats) and when chat features are enabled by both parties. in general, and iMessage delivers an end-to-end encrypted, multi-device system (as long as you're chatting to someone else using an iPhone or Apple device with the iMessage app).
End-to-end encrypted messaging apps
Signal is regarded as one of the most secure messaging apps on the Play Store. The mobile application allows for end-to-end encryption (using a tried-and-tested encryption algorithm) on all outgoing text, voice, and group-chat messages, and also allows for media and attachment sharing.
Other functions include self-destructing messages, local encrypted backups, and animated stickers.
All of the apps in this post are available on iPhone and iPad via the App Store.
Threema is an open-source chat app with some unique privacy solutions. It uses the NaCl cryptographic function to encrypt data and offers anonymous login via an ID key. Additionally, Threema has a QR "friend-addition" function along with voice, picture, video, and text encryption.
The app is particularly popular in Germany, and while it's not free ($3.99), you may decide it's a fair price to improve your privacy and security posture. It's available on both Android and iOS.
Wire is another open-source app that offers end-to-end encryption for messages, files, videos, and conference calls. It also comes with an array of enterprise-level functions, such as secure collaboration for businesses with included video conferencing tools and the ability to operate Wire on a company's own data centers.
Another feature sure to please power users is the presence of local decryption key storage, as opposed to storing keys in online, remote servers. Wire Personal is available on both iOS and Android for free; there's also an Enterprise subscription tier, which will allow you to access the extra business functions.
WhatsApp is one of the most widely-used voice and chat app on the planet, and it utilizes the VOIP standard to send voice data over the Internet. Since 2016, the Meta-owned app has used Signal's algorithm to encrypt data sent and received via end-to-end encryption. There are a variety of other functions that WhatsApp either employs or are currently undergoing Beta testing, including disappearing messages, chat history transfers, and end-to-end encrypted backups.
WhatsApp is fully free and available on both Android and iOS platforms, so you can chat securely across the divide.
5. Wickr Me
Wickr Me is a serious, privacy-focused app with plenty of security features. Specifically, the app supports configurable self-destructing messages and strips media from metadata like location and message times to increase your privacy.
In addition, Wickr Me offers a verification system enabling users to check each other's identity via short sequences of encrypted video messages. The company even has a bounty program offering up to $100,000 for users who find security flaws within the app.
For context, Wickr was acquired by Amazon in June 2021, causing some users to doubt the platform's privacy practices. Still, at the time of writing, the Wickr Me app remains one of the safest for end-to-end encrypted conversations.
Telegram only offers end-to-end encryption in "Secret Chats"
does not offer end-to-end encryption in regular chats as it has to store the information somewhere in its servers. That being said, the company's encryption within its "Secret Chats" feature is solid, at a similar level to WhatsApp and Signal.
Moreover, Telegram offers a great array of privacy and security features, including self-destructing media, proxy servers support, and a "delete my account" timer.
It also comes with a great variety of bells and whistles, such as the ability to lock and backup chats, a screen-sharing tool, and even a built-in photo and video editor.
Google Messages and iMessage are pretty solid (and fun) alternatives
While we believe that Signal tops all other options on our list when it comes to security and privacy, you can't go wrong with Threema, Wire, or WhatsApp if you want to make sure your chats with friends and family are as secure as possible. And if you're more interested in features than in end-to-end encryption, Google Messages has all the bells and whistles you could ever want.