Mattermost: Open Source Alternative to Slack
Secure team collaboration — messaging, playbooks, and integrations.
Mattermost is an open source messaging platform with 31k+ GitHub stars — a Slack alternative with full data control and compliance features.
Compare Mattermost with Microsoft Teams and Discord before you choose your stack.
Key features
Messaging
- Channels, DMs, and group messages
- File sharing with previews
- Threads and mentions
- Markdown formatting
Integrations
- Webhooks, bots, slash commands
- Jira, GitHub, GitLab integrations
- Playbooks for incident response
- Custom app framework
Compliance
- Data retention policies
- eDiscovery and legal hold
- Audit logging
- HIPAA and FedRAMP ready
Mattermost vs Slack
| Mattermost | Slack | |
|---|---|---|
| License | MIT (open source) | Proprietary |
| Deployment | Self-hosted available | Cloud SaaS |
| Data control | Your infrastructure | Vendor infrastructure |
| Customization | Full source access | Limited to vendor features |
| Cost | Free open-source software | Subscription or usage fees |
Choose Mattermost if you want open-source code, self-hosting options, and full control over your data and deployment.
Choose Slack if you prefer a managed proprietary product with vendor support and minimal setup.
Browse more open-source alternatives to Slack, or explore other tools in Collaboration.
At a glance
| License | MIT (core) |
| Stack | Go, React |
| Self-hosted | Yes |
| Cloud | mattermost.com |
| Database | PostgreSQL |
Self-hosting
docker run -d --name mattermost -p 8065:8065 mattermost/mattermost
Includes desktop and mobile apps.
FAQ
Is Mattermost a free alternative to Slack?
Yes. Mattermost is open source under MIT. You can self-host it at no software cost — you only pay for infrastructure or optional managed services.
How does Mattermost compare to Slack?
Mattermost gives you source code access, self-hosting, and data ownership. Slack is a proprietary product focused on managed convenience. See the comparison table above for a side-by-side breakdown.
Can I self-host Mattermost?
Yes. Mattermost supports self-hosted deployment, which is a core reason teams choose it over Slack. Check the Getting started or Self-hosting section for install commands.
Is Mattermost suitable for production?
Mattermost is actively maintained with a strong open-source community. Many teams run it in production as a Collaboration alternative to Slack. Review the At a glance table for license and stack details.
What are alternatives to Mattermost and Slack?
Browse alternatives to Slack for more open-source options, including tools compared to Microsoft Teams. Explore the full Collaboration category for related projects.
Screenshots
