Mattermost
A self-hostable team chat platform with channels, threads and integrations, popular for secure and technical teams.
- License
- GNU Affero General Public License v3.0Open source (OSI)
- GitHub stars
- 39k9.0k forks
- Latest release
- v11.11.1Sep 24, 2026
- Setup
- Needs a databaseSelf-hosted · Cloud
What the free edition leaves out
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 state it, so we do not guess.
| Feature | Free edition | Details | Source |
|---|---|---|---|
| SSO / SAML | Paid | SSO (SAML, OIDC, OAuth 2.0) is listed from the Professional plan; the editions page says SSO is being removed from Team Edition. | Source ↗ |
| Role-based access control | Paid | Granular role-based access control is listed under Enterprise. | Source ↗ |
| Audit logs | Paid | Advanced audit logging is listed on paid plans; the docs conflict on the free Entry edition. Basic JSON file logging works without a license. | 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 | Not confirmed | Whether the free edition includes the REST API, webhooks and slash commands was not confirmed. | 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, OIDC and OAuth 2.0 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. SSO, granular RBAC and advanced audit logging need paid tiers, which are quote-based. 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.
Facts checked on against the project’s official repository, documentation and pricing pages. GitHub numbers update automatically. How we verify.