Mattermost
Self-hosted Slack alternative for teams
Open Source
Self-Hostable
No Logs
Free (self-hosted) / $10/user/mo
Free self-hosted unlimited users. Cloud from $10/user/mo.
Quick Specs
| Open Source | ✓ Yes View code |
|---|---|
| E2E Encrypted | ✗ No |
| Zero Knowledge | ✗ No |
| Self-Hostable | ✓ Yes |
| No Logs Policy | ✓ Yes |
| Audited | ✗ No |
| Jurisdiction | United States |
| Pricing | Freemium |
About Mattermost
Open source Slack alternative you can host yourself. Channels, direct messages, file sharing, integrations. Not E2E encrypted but you control the server.
Best For
Organizations wanting Slack-like interface with self-hosting option
Security Considerations
A tool is only as effective as its implementation. Consider these factors:
- Configuration matters: Default settings may not match your threat model. Review security options carefully.
- Training is essential: Tools protect nothing if your team doesn't use them correctly or consistently.
- Integration points: Consider how this tool connects with your existing systems and what data flows between them.
- Continuity planning: Ensure you have backup access methods and know the recovery process.
Need help implementing this securely? Take our free assessment or book a discovery call.