Mattermost
CommunicationA self-hostable team chat platform with channels, threads and integrations, popular for secure and technical teams.
Open-source alternative to:
Slack
What the free edition leaves out
Scroll sideways to view all columns →The free edition is genuinely usable, but some team or enterprise features need a paid plan. “Not confirmed” means the official pages we read did not say, so we do not guess.
| Feature | Free edition | Details | Source |
|---|---|---|---|
| SSO / SAML | Not confirmed | The editions page lists SAML and OIDC under Professional and says SSO is being removed from the Team Edition; whether the free Entry edition includes SSO is not stated. | Source ↗ |
| Role-based access control | Paid | Granular role-based access control is listed under Enterprise. | Source ↗ |
| Audit logs | Not confirmed | The editions page does not say whether the free Entry edition includes audit logs. | Source ↗ |
| Multi-user / teams | Free | Free editions support multiple users and teams. Entry is guided at under 50 users (guidance, not a hard cap) and limits viewable history to 10,000 messages. | Source ↗ |
| Backups and restore | Not confirmed | Docs describe manual backup of the database, config and uploaded files; no built-in tool seen. | Source ↗ |
| API access | Free | The editions page says Entry has all features of Enterprise Advanced except the listed limits and omissions; APIs and webhooks are not among them. | Source ↗ |
| Support SLA | Paid | Free is community support; paid tiers add response-time commitments. | Source ↗ |
Best for
Technical or security-conscious teams that need self-hosted team chat and incident collaboration under their own control.
Why choose it over Slack
Self-hosting is officially supported, including air-gapped deployments on the top tier. SSO supports SAML and OIDC on paid plans, and the source is available under AGPL-3.0.
Where it falls short
The free Entry edition limits viewable and searchable history to 10,000 messages. The Docker method is not recommended for production, and you manage your own database, backups and upgrades.
Open-source alternative to
- Slack — Mattermost is a self-hostable team chat platform with channels, threads and integrations, offered as an alternative to Slack.
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