WhatsApp Messenger

Free

WhatsApp Messenger is an instant messaging platform owned by Facebook.

Tox

Open Source

Tox is a peer-to-peer instant-messaging and video-calling protocol that offers end-to-end encryption.

Signal

Open Source

Signal is the most scalable encryption tool.

Wire

Free

Wire is a cross-platform, encrypted instant messaging client created by Wire Swiss. It is available for iOS, Android, Linux, Windows, macOS and Web browser cl…

ChatSecure

Open Source

ChatSecure is a messaging application for iOS which allows OTR and OMEMO encryption for the XMPP protocol.

Matrix.org

Open Source

Matrix is an open protocol for real-time communication. It is designed to allow users with accounts at one communications service provider to communicate with…

Zulip

Open Source

Zulip is a chat and collaborative software.

Silence.im

Open Source

Silence.im is an encrypted text messaging service.

Slack

Freemium

Slack is a cloud-based team collaboration tool.

Discord

Free

Discord is a freeware proprietary VoIP application designed for gaming communities.

Jitsi

Open Source

Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.

Ring

Open Source

Ring (SFLphone) is an open-source SIP-compatible softphone and instant messenger for Linux, Microsoft Windows, OS X and Android.

Threema

Commercial

Threema is an encrypted instant messaging application for iOS, Android and Windows Phone.

Sicher

Commercial

Sicher is a freeware instant messaging application for iOS, Android, and Windows Phone. Sicher allows users to exchange end-to-end encrypted text messages, me…