Rocket.Chat
Self-hosted team chat with voice, video, and omnichannel support
Key differentiator
Rocket
45,303 stars13,569 forksTypeScript
Alternative To
Best Alternatives to Slack
A channel-based messaging platform that brings teams together with real-time communication, file sharing, and extensive app integrations.
Why people leave Slack
Editorial intro has not been added yet.
12 alternatives to Slack
Free
Valour
Open source Discord alternative with flexible community tools
Key differentiator
It is an open-source, community-driven platform offering flexible chat, economy, and item systems built on Blazor & WebAssembly
382 stars38 forksC#
Prose
Decentralized open source workplace with chat and docs
Key differentiator
It is a decentralized, open-source workplace communication platform powered by XMPP, offering secure and transparent team messaging
36 stars4 forksRust
VoceChat
Lightweight self-hosted chat server with embeddable widget
Key differentiator
It is a lightweight, self-hostable chat application and framework built with Rust, offering private in-app messaging and AI bot integration
52 stars10 forksTypeScript
Adapt
Lightweight self-hosted messaging platform for teams
Key differentiator
It is a lightweight, customizable, and open-source messaging platform focused on user privacy and community building
1 stars0 forks
SpacebarChat
Free open source Discord reimplementation with full API parity
Key differentiator
It is a free, open-source Discord reimplementation, offering self-hosted, secure communication similar to Slack and Rocket
2,149 stars303 forksTypeScript
Converse.js
Self-hosted web-based XMPP chat client for any server
Key differentiator
An open-source, web-based XMPP chat client offering self-hosting, customization, and end-to-end encryption for secure messaging
3,248 stars820 forksJavaScript
Revolt
Self-hosted open source Discord alternative with servers
Key differentiator
Revolt is a self-hosted Discord alternative with servers, channels, voice chat, and bot support, built for community privacy
2,335 stars56 forks
Matrix
Open protocol for secure, decentralized messaging and VoIP
Key differentiator
An open protocol for secure, decentralized communication, enabling real-time messaging, VoIP, and data transfer across platforms
12,082 stars2,118 forksPython
Zulip
Organized team chat with threaded conversations, self-hostable
Key differentiator
An organized team chat app designed for distributed teams, offering features like threaded conversations and powerful search
25,166 stars9,825 forksPython
Mattermost
Team messaging for security-sensitive teams with air-gap support
Key differentiator
Mattermost is a self-hosted team messaging platform with channels, threads, integrations, and workflow automation for security-sensitive organizations
36,696 stars8,612 forksTypeScript
Wire
End-to-end encrypted messaging, voice, and file sharing
Key differentiator
A secure collaboration platform offering encrypted messaging, voice, video, and file sharing for privacy-conscious teams and enterprises
2,767 stars334 forksHaskell