Mattermost vs Rocket.Chat
| Tagline | Open-source, self-hostable Slack alternative for secure team messaging and collaboration | Fully customizable open-source communications platform and Slack alternative |
| Category | Team Chat & Collaboration | Team Chat & Collaboration |
| Replaces | Slack, Microsoft Teams, Discord | Slack, Microsoft Teams, Discord |
| GitHub stars | 39k | 46k |
| Language | Go | TypeScript |
| License | MIT | MIT |
| Self-host difficulty | 3/5 Moderate | 3/5 Moderate |
| Deploy options | One-Click Docker Docker Compose Kubernetes Manual | One-Click Docker Docker Compose Kubernetes Manual |
| Managed hosting | ||
| Last updated | 2 days ago | 2 days ago |
| View repo | View repo |
Where each falls short
The honest trade-offs — what you give up with each, versus the proprietary tools they replace.
Mattermost
- Many advanced features (LDAP/AD, SAML/SSO, compliance exports, high availability) are gated behind paid Enterprise tiers
- Search and message UX feel less polished than Slack
- Voice/video calling is more limited than Teams' full meetings stack
- Smaller third-party app/integration marketplace than Slack
Rocket.Chat
- Resource-heavy (Node.js + MongoDB) and can be slow at scale on modest hardware
- Some enterprise features (engagement dashboard, scalability, advanced auth) require a paid plan
- UI can feel cluttered compared to Slack
- Mobile apps have historically lagged the web client in polish
Bottom line
Both are a similar lift to self-host; choose Rocket.Chat for the larger community and ecosystem. Open each guide below for deploy steps and the full feature gap.
Mattermost
Open-source, self-hostable Slack alternative for secure team messaging and collaboration
Rocket.Chat
Fully customizable open-source communications platform and Slack alternative