Best Open Source Team Chat & Messaging Tools in 2026
Real-time messaging platforms for team communication, group chats, and workplace collaboration.
The most popular pick this year is Discourse with 47,011 GitHub stars, but all 7 options below are worth considering depending on your needs.
7 open source team chat & messaging tools — ranked by GitHub stars. Browse all
Discourse
A platform for community discussion. Free, open, simple.
Discord
Rocket.Chat
The communications platform that puts data protection first.
Skype
Mattermost
Mattermost is an open source platform for secure collaboration across the entire software development lifecycle..
Discord
Zulip
Open-source team chat with a unique topic-based threading model that makes it easy to follow multiple conversations.
Slack
Element
Open-source Matrix client for secure, decentralized messaging, voice, and video — runs on your own server.
Discord
Mumble
Low-latency, open-source voice chat built for gaming — self-host your own server with no subscription required.
Discord
Raven
Simple, open source team messaging platform
DiscordHow we rank these tools
Tools are ranked by GitHub stars as a proxy for community adoption and trust. Stars reflect how many developers found a project valuable enough to bookmark — a reasonable signal for quality in the open source world. We only list tools that are actively maintained and open source.
Looking for tools you can run yourself? Browse self-hosted team chat & messaging tools →