Free

Telegram is a free cloud-based instant messaging platform.

Signal

Open Source

Signal is the most scalable encryption tool.

Off-the-Record Messaging

Open Source

Off-the-Record Messaging (OTR) is a cryptographic protocol that provides encryption for instant messaging conversations.

Threema

Commercial

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

Torchat

Open Source

TorChat is a decentralized anonymous instant messenger that uses Tor hidden services as its underlying network. It provides cryptographically secure text mess…

Conversations

Freemium

Conversations is an open source XMPP/Jabber client for the Android platform.

Otr.to

Open Source

Otr.to is a browser based chat client.

Bit Chat

Open Source

Bit Chat is a secure, peer-to-peer, open source instant messenger with end-to-end encryption.

Disa

Open Source

Disa is your new messaging hub. Conversations from different services can seamlessly be joined together, or disbanded within seconds.

Wickr

Free

Wickr is an instant messenger application.

Pidgin-Encryption

Open Source

Pidgin-Encryption transparently encrypts your instant messages with RSA encryption.

Tox

Open Source

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

Ring

Open Source

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

Xabber

Open Source

Xabber (XMPP and Jabber) is a XMPP client for the Android Operating System.

Bitmessage

Open Source

Bitmessage is a decentralized, encrypted, peer-to-peer, trustless communications protocol that can be used by one person to send encrypted messages to another…

Psi+

Open Source

Psi is a cross-platform powerful XMPP/Jabber client (Qt, C++) designed for the Jabber power users. Psi+ is a development branch of Psi IM XMPP/Jabber client.

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…

Finch

Open Source

Finch is a console-based IM program that lets you sign on to AIM, Jabber, MSN, Yahoo!, and other IM networks. It runs on Unixes. It uses GLib and ncurses.