Open Source Alternatives to Slack
Rocket.Chat
The secure communications platform for mission-critical operations.
★ 46,238 Updated: Oct 2026 Status: Active
Mattermost
Mission-critical collaboration for technical teams
★ 39,305 Updated: Oct 2026 Status: Active
Zulip
Chat for distributed teams.
★ 26,020 Updated: Oct 2026 Status: Active
Element
Secure collaboration and messaging
★ 13,550 Updated: Oct 2026 Status: Active
Fosscord
Open-source Discord-compatible chat platform
★ 6,715 Updated: Apr 2026 Status: Slowing
Cinny
Matrix client for desktop and web
★ 3,926 Updated: Oct 2026 Status: Active
Revolt
An open-source, privacy-respecting chat platform prioritizing user freedom.
★ 2,321 Updated: Feb 2026 Status: Slowing
Movim
Decentralized social platform on XMPP
★ 2,060 Updated: Oct 2026 Status: Active
Twake
The open Digital Workplace for team collaboration.
★ 1,921 Updated: Feb 2026 Status: Slowing
Cabal Desktop
P2P community chat platform
★ 914 Updated: Feb 2024 Status: Inactive
A
AJAX Chat
Customizable web chat in JavaScript and PHP
★ 551 Updated: Jul 2026 Status: Active
W
Wire
The most secure collaboration platform.
Status: Unknown