Free Alternative to Slack
5 free & open-source projects that replace Slack.
Compare at a Glance
| vs Slack |  rocket-chat |  mattermost |  buzz |  zulip |  arcane |
|---|---|---|---|---|---|
| Stars | 46k | 39k | 33k | 26k | 7.3k |
| Forks | 14k | 9.0k | 4.3k | 10k | 306 |
| Contributors | 30 | 30 | 30 | 30 | 30 |
| Last Commit | Mar 6, 2026 | Mar 6, 2026 | Aug 23, 2026 | Feb 7, 2026 | Mar 6, 2026 |
| License | MIT | GNU GPL-3.0 | Apache-2.0 | Apache-2.0 | BSD-3-Clause |
| Language | TypeScript | TypeScript | Rust | Python | Go |
Tired of paying for Slack, dealing with data privacy concerns, or wishing you had more control over your team's communication and data? There's a powerful, secure, and completely open-source solution that's changing how teams connect.
Arcane is a privacy-focused team chat platform designed for modern teams who value security and independence. It offers robust channels for organized discussions, seamless workflow automation to boost productivity, and the complete freedom of open-source software, allowing you to easily self-host and maintain full control over your critical communication data.
- 💬 Team Chat
- 👥 Secure Channels
- ⚙️ Workflow Automation
- 🔒 Privacy-Focused
- 🏡 Self-Hosted Option
With Arcane, you get enterprise-grade features without the enterprise price tag. It's completely free & open-source, offering no watermarks, no hidden fees, and absolutely no subscriptions. Enjoy truly free software, forever.
Experience secure, flexible, and powerful team communication without the recurring costs. Discover Arcane on Fossy today and take back control: https://fossy.dev/getarcaneapp/arcane
