One of the most popular alternatives to Mattermost is Element, which is open source and free for personal use. Other popular alternatives are Discord, Matrix, Stoat Chat and Slack. You're spoiled for choice with Group Chat Apps like Mattermost: we list more than 100 alternatives for the web, Android, iPhone, Windows and Mac.
A Collaboration workspace that acts as a virtual office for remote workers and distributed teams. Provides features like chat, voice channels, screen sharing, meeting rooms & task management and more.
This simple Matrix client written in Python allows you to send and receive messages and files, verify other devices, and interact with your Matrix account or other Matrix users in many ways. You use it from the terminal (CLI) or integrate it into other simple Python programs.
Get more done – with Grape (also called ChatGrape). Grape is an European Business-Messenger with an On-Premise and Cloud solution. It is GDPR compliant and prioritizes data security and safety.
Germany
EU
PrivMX Fusion is safe and easy collaboration software for all kinds of teams, with virtual workspace protected by end-to-end encryption. Each team uses desktop/laptop client software and its own (zero-knowledge) PrivMX Team Server.
PolandEU
The future of Team collaboration. Secure. Cross platform. Manage Teams, Groups, Private & Public Channels. Invite. Meet. Work. Automate with over 700'000 Apps. Built-in Webinar & Webmeetings. Available as PrivateCloud or On Premise. Decentralized.
Cardinal is a team communication and knowledge management platform that avoids negative motivations like fear of missing out and hero syndrome and instead helps teams build efficient and effective communication through using the right tool for the job.
United States
JANDI is a group-oriented enterprise messaging platform with an integrated suite of collaboration tools for workplace.
United States
Instant Messaging (IM) server for internal and secure collaboration over corporate and business networks. It provides Active Directory support, message and file archiving, offline messaging and document distribution with a strong encryption of data.
Russia
SadnessChat SadnessChat is a free, real-time chat platform built for real conversations. Whether you're hanging out with friends or building a community, SadLounge has everything you need.
Team chat platform with AI coworker in every channel, supporting commands, code generation, and direct in-chat results. Offers familiar channels, threads, DMs, web-based access, automation, real-time collaboration, secure workflows, and reduced tool switching.
SwedenEU
MongooseIM is aimed at large, complex enterprise level projects, where real-time communication is critical for business success. It provides high availability, ease of deployment, development and reliability in production.
France
United Kingdom