Top Open Source Team Chat & Messaging Tools in 2026
A curated collection of the 16 best free and open-source Team Chat & Messaging tools in 2026. Compare features, GitHub stars, tech stacks, and self-hosted software.
Zulip
Organized team chat for distributed teams
Stars25,775Last commit11d agoLicenseApache-2.0
Wire
Secure end-to-end encrypted messenger for organizations
Stars2,544Last commit8mo agoLicenseGPL-3.0UnInbox
Collaborative email for teams to get work done
Stars1,757Last commit6mo agoLicenseOpen Source
Twake Chat
Secure open-source messenger for professionals
Stars163Last commit11d agoLicenseAGPL-3.0
Quiet
Peer-to-peer encrypted messaging without servers
Stars2,642Last commit13d agoLicenseGPL-3.0
Stoat
Open-source group chat for communities
Stars3,256Last commit11d agoLicenseOpen Source
Rocket.Chat
Secure team chat with voice, video & AI
Stars46,033Last commit11d agoLicenseOpen Source
Campfire
Self-hosted Slack alternative with code access
Stars4,528Last commit13d agoLicenseMITMezon
All-in-one community platform with AI agents
Stars1,650Last commit12d agoLicenseOpen Source
Mattermost
Secure collaboration platform for mission-critical teams
Stars38,913Last commit10d agoLicenseOpen Source
Macro Chat
Team chat with AI agents and unified workspace
Stars4,064Last commit11d agoLicenseAGPL-3.0Fluxer
Privacy-first open source chat app with voice & video
Stars10,138Last commit10d agoLicenseAGPL-3.0
Ethora
Unified chat & AI SDK for web, iOS & Android
Stars543Last commit11d agoLicenseApache-2.0
Element
Secure decentralized team messaging & collaboration
Stars13,408Last commit10d agoLicenseAGPL-3.0
Cinny
Privacy-focused Matrix client
Stars3,865Last commit27d agoLicenseAGPL-3.0
