Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].




The best alternative to Slack is Conversations, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to Slack and many of them are so hopefully you can find a suitable replacement. Other interesting alternatives to Slack are Twake, Mirotalk, Nextcloud Talk and Movim.
Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].




Twake is a real-time teamwork platform. It is a suite of collaborative tools that includes the specificities of some bestsellers (Slack, Trello, Google Drive...). We provide professional messaging, storage space, online collaborative editors (Words, Excel, PowerPoint), task...




Powered by WebRTC, Real-time video call, chat room and screen sharing entirely browser based.



Self-hosted communication platform with secure audio, video, chat, web conferencing, screensharing, advanced encryption, and metadata privacy, running on user-controlled servers, supporting web and mobile apps, and eliminating third-party data exposure.




Decentralized social and blog platform based on XMPP, enabling self-hosting, cross-network chat, video calls, and group collaboration. Users control and migrate their data, communicate across various networks, and access services from any node while preserving privacy and open-source principles.




All you need in a team collaboration tool dedicated to small efficient teams. Chat, notes, drive, online collaborative edition, calendars, news, spaces, notifications...
Dino is a modern open-source chat client for the desktop. It focuses on providing a clean and reliable Jabber/XMPP experience while having your privacy in mind. Using GTK+/Vala.



eXo Platform is an all-in-one digital workplace solution that helps you connect, align and engage your teams around a single interface. You can use it to improve company and peer-to-peer communication, boost collaboration and manage company knowledge.








Zenchat combines messaging and task management, letting users turn messages into tasks for streamlined collaboration. It supports task-related and topic-based chats while integrating with the Zenkit Suite. Features include SSO, SCIM provisioning, and audio/video messaging, with free and paid plans available.




Stackfield is a Slack-alternative for chat, collaboration, calendaring and file-sharing. It enables encrypted chatting (end-to-end encryption) and is hosted in Germany.




Fleep is a messenger for your teams and projects. It enables communication within and across organizations - be it your team chats, project communication or 1:1 conversations.




I like Twake as an alternative to Slack because it is open-source.