17 Best Open Source Microsoft Teams Alternatives
A curated collection of the 17 best open source and self-hosted alternatives to Microsoft Teams in 2026.
Looking for a free, privacy-friendly, or self-hosted replacement for Microsoft Teams in 2026? The top open-source alternative is Macro Chat — Team chat app with inline threads, mention-based sharing, a unified inbox for chat and email, and an AI agent that works across your full workspace..
Other highly rated open-source Microsoft Teams alternatives include Rocket.Chat, Buzz and Mattermost.
Team chat app with inline threads, mention-based sharing, a unified inbox for chat and email, and an AI agent that works across your full workspace.
Team chat app with inline threads, mention-based sharing, a unified inbox for chat and email, and an AI agent that works across your full workspace.
Open source communication platform combining messaging, voice, video, and AI for organizations that need full data control, air-gapped deployments, and zero-trust security.
Open source communication platform combining messaging, voice, video, and AI for organizations that need full data control, air-gapped deployments, and zero-trust security.
Workspace that combines team chat, project planning, and git management with AI agents that collaborate alongside your team on shared context.
Workspace that combines team chat, project planning, and git management with AI agents that collaborate alongside your team on shared context.
Mattermost provides a flexible, open-source platform for secure team collaboration, designed for organizations with strict security and privacy requirements.
Mattermost provides a flexible, open-source platform for secure team collaboration, designed for organizations with strict security and privacy requirements.
Nextcloud offers on-premises file sync, sharing and collaboration platform with advanced security and privacy features.
Nextcloud offers on-premises file sync, sharing and collaboration platform with advanced security and privacy features.
Host encrypted video conferences directly in your browser, deploy on your own servers, or integrate into applications - all with this powerful open source platform.
Host encrypted video conferences directly in your browser, deploy on your own servers, or integrate into applications - all with this powerful open source platform.
Zulip is an open-source team chat app that uses threaded conversations to keep communication organized and efficient for teams of all sizes.
Zulip is an open-source team chat app that uses threaded conversations to keep communication organized and efficient for teams of all sizes.
Open-source platform for encrypted communication, file sharing, and collaboration based on the Matrix protocol.
Open-source platform for encrypted communication, file sharing, and collaboration based on the Matrix protocol.
Create customizable virtual workspaces for remote teams to interact naturally, host events, and collaborate through spontaneous conversations and scheduled meetings.
Create customizable virtual workspaces for remote teams to interact naturally, host events, and collaborate through spontaneous conversations and scheduled meetings.
Install your own group chat system with @mentions, DMs, and mobile support. One-time purchase, no monthly fees. Includes full source code for customization.
Install your own group chat system with @mentions, DMs, and mobile support. One-time purchase, no monthly fees. Includes full source code for customization.
Local-first collaboration platform combining real-time chat, rich text pages, databases, and file management in a single self-hostable workspace.
Local-first collaboration platform combining real-time chat, rich text pages, databases, and file management in a single self-hostable workspace.
Cinny offers a simple, elegant, and secure interface for Matrix-based conversations, protected by end-to-end encryption.
Cinny offers a simple, elegant, and secure interface for Matrix-based conversations, protected by end-to-end encryption.
A comprehensive collaboration platform offering end-to-end encrypted messaging, file sharing, and video calls with enterprise-grade security and compliance features.
A comprehensive collaboration platform offering end-to-end encrypted messaging, file sharing, and video calls with enterprise-grade security and compliance features.
Build your own community space for gaming, chatting, and hanging out with friends worldwide. Customize your environment for the perfect social experience.
Build your own community space for gaming, chatting, and hanging out with friends worldwide. Customize your environment for the perfect social experience.
Streamline team communication with shared inboxes, unlimited email addresses, and customizable workflows. Perfect for modern businesses seeking organized email management.
Streamline team communication with shared inboxes, unlimited email addresses, and customizable workflows. Perfect for modern businesses seeking organized email management.
Free Matrix-based messenger with end-to-end encryption, multi-platform bridges, and on-premise deployment. Connect across 30+ networks securely.
Free Matrix-based messenger with end-to-end encryption, multi-platform bridges, and on-premise deployment. Connect across 30+ networks securely.
Open source chat server with end-to-end encryption, clustering support, and comprehensive messaging features for building real-time communication apps
Open source chat server with end-to-end encryption, clustering support, and comprehensive messaging features for building real-time communication apps
About Microsoft Teams
Cloud-based collaboration app for messaging, video calls, meetings, and file sharing. Integrates with Office 365 for seamless communication and productivity.