gomuks
Best for self-hosting
Why teams pick it
Teams deploying self-hosted Matrix infrastructure
Open-source alternatives to Slack
Compare community-driven replacements for Slack in team chat platforms workflows. We curate active, self-hostable options with transparent licensing so you can evaluate the right fit quickly.
Slack
Slack enables real-time messaging, file sharing, and integrations with thousands of tools. It supports channels, threads, and enterprise-grade security and compliance features for organizations.Read more
Key stats
- 15Alternatives
- 6Support self-hosting
Run on infrastructure you control
- 14Active development
Recent commits in the last 6 months
- 5Permissive licenses
MIT, Apache, and similar licenses
Counts reflect projects currently indexed as alternatives to Slack.
Start with these picks
These projects match the most common migration paths for teams replacing Slack.
Rocket.Chat
Privacy-first alternative
Why teams pick it
Strong focus on data protection and privacy
All open-source alternatives
Rocket.Chat
Secure, customizable communication platform for teams and customers
Active developmentPrivacy-firstFast to deployTypeScript
Why teams choose it
- Role‑based access control for secure internal and cross‑company collaboration
- Omnichannel messaging across WhatsApp, SMS, email, and web chat
- Self‑hosted AI assistants and a customizable workspace
Watch for
Self‑hosting can require DevOps expertise
Migration highlight
Secure internal collaboration for a multinational railway
Employees across regions communicate in real time while meeting GDPR and internal security policies.
gomuks
Lightweight Matrix client built with Go and mautrix
Self-host friendlyActive developmentPrivacy-firstGo
Why teams choose it
- Built on mautrix framework for robust Matrix protocol support
- Web-based interface with planned terminal frontend
- Lightweight Go backend with TypeScript frontend
Watch for
Terminal interface currently unavailable in active branch
Migration highlight
Self-Hosted Team Communication
Deploy gomuks on internal infrastructure for encrypted team messaging without third-party dependencies
Koishi
Cross-Platform Chatbot Framework with Rich Plugin Ecosystem
Active developmentPermissive licenseIntegration-friendlyTypeScript
Why teams choose it
- Web console with online plugin marketplace for zero-code setup
- 1000+ plugins covering platforms, databases, and business features
- Full TypeScript support with rich IntelliSense and type safety
Watch for
Documentation and community resources primarily in Chinese
Migration highlight
Multi-Platform Community Management
Synchronize messages and moderation across QQ, Discord, and Telegram with unified data storage and cross-platform user tracking.
Cinny
Simple, elegant Matrix client for modern instant messaging
Self-host friendlyActive developmentPrivacy-firstTypeScript
Why teams choose it
- Clean, modern interface focused on usability and accessibility
- Self-hostable with Docker or static file deployment
- Web and desktop application options for flexible access
Watch for
Subdirectory deployment requires manual rebuild with custom base path
Migration highlight
Privacy-Conscious Team Communication
Self-host Cinny on internal infrastructure to maintain full control over messaging data while providing team members with an intuitive chat interface
Mattermost
Secure, extensible team collaboration platform for modern workflows
Active developmentFast to deployIntegration-friendlyTypeScript
Why teams choose it
- Self‑hosted single binary with PostgreSQL backend
- Built‑in voice calling and screen sharing
- AI integration for automated workflows
Watch for
Requires own infrastructure and PostgreSQL management
Migration highlight
DevSecOps pipeline coordination
Developers receive real‑time security alerts in chat, trigger automated scans via slash commands, and track remediation status.
Zulip
Threaded team chat that blends email clarity with real‑time speed
Active developmentPermissive licenseFast to deployPython
Why teams choose it
- Topic‑based threading keeps conversations organized
- Supports both live chat and asynchronous discussion
- Self‑hostable via Ubuntu/Debian packages, Docker, or cloud images
Watch for
Self‑hosting requires server management expertise
Migration highlight
Cross‑functional project coordination
Threads keep each feature discussion separate, preventing information overload.
Misago
Modern, feature‑rich forum platform built with Django and React
Active developmentFast to deployIntegration-friendlyPython
Why teams choose it
- OAuth support for 50+ providers
- Granular permission and role system
- Rich moderation tools with queues and edit logs
Watch for
No official test suite for frontend assets
Migration highlight
Tech community with multi‑provider SSO
Members log in via Google, GitHub, or Steam, reducing friction and centralizing authentication.
Spacebar
Self‑hosted, Discord‑compatible chat, voice, and video platform.
Fast to deployIntegration-friendlyAI-powered workflows
Why teams choose it
- Discord‑compatible API for seamless bot integration
- Fully self‑hostable server with admin dashboard
- Extensible plugin system and cross‑platform theming
Watch for
Self‑hosting requires technical setup and maintenance
Migration highlight
Remote team collaboration
Secure, customizable chat, voice, and video channels hosted on the organization’s own servers.
Bluesky
Open-source React Native client for Bluesky decentralized social network
Self-host friendlyActive developmentPermissive licenseTypeScript
Why teams choose it
- Cross-platform React Native architecture for web, iOS, and Android
- Native integration with AT Protocol decentralized social framework
- MIT-licensed with software patent non-aggression pledge
Watch for
Contribution guidelines prioritize team bandwidth over community PRs
Migration highlight
Enterprise Social Network
Fork the codebase to deploy a private Bluesky instance with corporate branding and internal authentication systems
Element
Matrix web client for secure, decentralized team communication
Self-host friendlyActive developmentPrivacy-firstTypeScript
Why teams choose it
- End-to-end encrypted messaging on the decentralized Matrix network
- Self-hostable web client with full configuration control
- Cross-platform support: browser, desktop (Electron), and mobile web
Watch for
Windows users cannot use yarn dist build script
Migration highlight
Enterprise Self-Hosted Collaboration
Deploy Element on internal infrastructure to maintain full control over sensitive communications while leveraging Matrix federation for external partnerships.
Apache Answer
Open-source Q&A platform for teams of any scale
Self-host friendlyActive developmentPermissive licenseGo
Why teams choose it
- Docker-ready deployment with single-command setup for rapid installation
- Plugin system for custom extensions without modifying core codebase
- Built with Go backend and React/TypeScript frontend for performance and maintainability
Watch for
Requires Golang 1.23+ and Node.js 20+ for building from source
Migration highlight
Open Source Project Support Forum
Centralize community questions, reduce duplicate issues on GitHub, and build searchable knowledge base for common problems
Flarum
Delightfully simple discussion platform for modern communities
Active developmentPermissive licenseIntegration-friendlyPHP
Why teams choose it
- Lightweight PHP architecture with Mithril-powered interface for fast performance
- Responsive, human-centered design that works beautifully out-of-the-box
- Powerful Extension API for deep customization and integration
Watch for
Younger platform with smaller ecosystem compared to legacy forum software
Migration highlight
Product Support Community
Deploy a clean, fast forum where customers find answers and engage with support teams without navigating cluttered interfaces
NodeBB
Real-time forum platform built on Node.js and websockets
Active developmentFast to deployIntegration-friendlyJavaScript
Why teams choose it
- Real-time notifications and live updates via websockets
- Flexible theming with Bootstrap 5, SCSS, and CSS
- Extensible plugin architecture for custom functionality
Watch for
Requires Node.js 20+ and a compatible database
Migration highlight
Live Q&A during webinars
Attendees see questions and answers instantly, fostering engagement
Discourse
Open-source community platform with discussions, chat, and plugins
Self-host friendlyActive developmentPrivacy-firstRuby
Why teams choose it
- Discussion topics and real-time chat in a unified platform
- Extensive plugin ecosystem including AI chatbots and data analysis tools
- Full theme customization with official and community options
Watch for
Requires Ruby 3.3+, PostgreSQL 13, and Redis 7 for self-hosting
Migration highlight
Open-Source Project Support Community
Centralized hub for user questions, feature discussions, and real-time contributor chat, with full control over community data and branding
ejabberd
Scalable real-time messaging platform with XMPP, MQTT, and SIP
Active developmentFast to deployIntegration-friendlyErlang
Why teams choose it
- Native XMPP server with extensive XEP support
- Built-in MQTT broker for IoT messaging
- Integrated SIP service for voice and video
Watch for
Requires Erlang knowledge for deep customization
Migration highlight
Corporate instant messaging and presence
Provides secure, federated chat with XMPP, supporting millions of users and integration with existing directories.
Choosing a team chat platforms alternative
Teams replacing Slack in team chat platforms workflows typically weigh self-hosting needs, integration coverage, and licensing obligations.
- 6 projects let you self-host and keep customer data on infrastructure you control.
- 14 options are actively maintained with recent commits.
Tip: shortlist one hosted and one self-hosted option so stakeholders can compare trade-offs before migrating away from Slack.