Mattermost vs SimpleX Chat
| Tagline | Open-source, self-hostable Slack alternative for secure team messaging and collaboration | The most private chat platform — no user IDs, double ratchet E2E encryption |
| Category | Team Chat & Collaboration | Team Chat & Collaboration |
| Replaces | Slack, Microsoft Teams | Slack, Discord, Microsoft Teams |
| GitHub stars | 38k | 11k |
| Language | Go | Haskell |
| License | MIT | AGPL-3.0 |
| Self-host difficulty | 3/5 Moderate | 4/5 Involved |
| Deploy options | One-Click Docker Docker Compose Kubernetes Manual | Docker Manual |
| Managed hosting | ||
| Last updated | today | today |
| 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
SimpleX Chat
- No web client; primarily mobile-focused with a desktop CLI and early-stage desktop app.
- Self-hosting the SMP server requires manual Haskell build or Docker and knowledge of relay configuration.
- No workspace/org structure, channels, or administrative tooling suitable for business teams.
- Integrations and bots ecosystem is minimal compared to Slack or Discord.
Bottom line
Choose Mattermost if you want the lower-effort setup; choose Mattermost 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
SimpleX Chat
The most private chat platform — no user IDs, double ratchet E2E encryption