Rocket.Chat
Team ChatOpen-source team chat and collaboration platform
Replaces Slack, Microsoft Teams
Best Multi-User Team Chat for self-hosting
The 7 best Multi-User team chat you can self-host, ranked by community traction.
Mattermost
Team ChatSecure collaboration for developer teams
Replaces Slack, Microsoft Teams
Zulip
Team ChatThreaded team chat that combines email and chat
Replaces Slack, Microsoft Teams
Let's Chat
Team ChatSelf-hosted chat app for small teams
Replaces Slack, HipChat
Revolt
Team ChatOpen-source chat platform for communities
Replaces Discord
Spark IM
Team ChatCross-platform XMPP instant messaging client
Replaces Slack, Skype
Virola Messenger
Team ChatInstant messaging and collaboration tool with private and group chat
No apps match these filters.
Every option here is open-source and self-hostable, tagged Multi-User within the team chat category. Compare them on the individual app pages for setup difficulty and resource requirements.