Mattermost
Open source platform for secure collaboration across the entire software development lifecycle
About Mattermost
Mattermost is a self-hosted, open-core collaboration platform designed for mission-critical work. It provides secure team messaging, voice calling, screen sharing, workflow automation via Playbooks, and deep integrations with DevOps tools like GitLab, Jenkins, and PagerDuty. Trusted by organizations in defense, government, healthcare, and finance, Mattermost gives teams full data sovereignty and compliance control.
Pros & Cons
Pros
- Full data sovereignty with self-hosted deployment on your own infrastructure
- Open-source core with MIT license allows deep customization and auditability
- Enterprise-grade security including E2EE, MFA, SSO, and compliance certifications
- Rich DevOps integrations with CI/CD, monitoring, and incident management tools
- Works in air-gapped, disconnected, and edge environments for defense and government use
- Active community and extensible plugin architecture
Cons
- Self-hosting requires technical expertise for setup and ongoing administration
- UI feels less polished compared to mainstream alternatives like Slack or Teams
- Mobile app can experience performance lag and feels less refined than desktop
- Steep learning curve for smaller teams without dedicated IT support
- Advanced features often require additional configuration or paid tiers
Key Features
Channels & Direct Messaging
Organized team communication with public/private channels, direct messages, threads, and file sharing
Collaborative Playbooks
Automated workflow checklists for incident response, release management, and operational procedures
Voice Calls & Screen Sharing
Built-in voice and video calling with screen sharing for real-time collaboration without third-party tools
DevOps Integrations
Native integrations with GitLab, Jenkins, GitHub Actions, Prometheus, Grafana, PagerDuty, and Opsgenie
Self-Hosted Deployment
Deploy on your own infrastructure for full data custody, including air-gapped and edge environments
AI Integration
Built-in AI capabilities for message summarization, content generation, and workflow assistance
Enterprise Security
End-to-end encryption, MFA, SSO, granular permissions, audit logs, and compliance with industry standards
Burn-on-Read Messages
Set visibility time limits on sensitive messages and posts to minimize data exposure risks
Custom Integrations & Plugins
Extensible platform with webhooks, slash commands, bots, and a plugin marketplace
Pricing
- Unlimited message history
- Channels & direct messaging
- File sharing
- Voice calls
- Community support
- Self-hosted deployment
- Everything in Free
- SSO with SAML 2.0 & OIDC
- Guest accounts
- Read-only channels
- Advanced permissions
- Priority support
- Everything in Professional
- Enterprise-scale search
- High availability clustering
- Advanced compliance & audit
- Custom data retention policies
- Dedicated support
- Everything in Enterprise
- Multi-domain operations
- Burn-on-read messages
- Strictest security controls
- Advanced operational integrity
- Priority engineering support
Best For
DevSecOps Collaboration
Secure ChatOps platform for coordinating software delivery, pipeline alerts, and code reviews with integrated CI/CD tool notifications
Incident Response & Management
Automate incident handling with Playbooks that track diagnostics, assign tasks, and integrate with PagerDuty and Opsgenie for faster resolution
Secure Government & Defense Communication
Deploy on classified or air-gapped networks with full data custody for mission-critical team communication
Regulated Industry Collaboration
Meet healthcare (HIPAA) and financial compliance requirements with audit logs, data retention, and encryption controls
Open Source Slack Alternative
Replace proprietary messaging platforms with a customizable, self-hosted solution that gives organizations full control over their data
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Featured In
7 Best Open-Source Team Communication Platforms You Can Self-Host (2026)
Best overall Slack replacement for engineering and DevOps teams. The familiar interface ensures fast adoption, while Playbooks and security features justify choosing it over the original.
Mattermost vs Rocket.Chat: Which Self-Hosted Slack Alternative Wins? (2026)
Best for engineering and IT teams who want a focused, Slack-like self-hosted messaging platform with native DevOps integrations and minimal deployment overhead.
Tools That Fix the 'Too Many Slack Channels' Problem (2026)
Best for teams that need Slack-style messaging with admin controls to prevent channel sprawl — Mattermost's governance features and self-hosting solve overload at the organizational level.
5 Tools That Stop Your Team From Using Personal WhatsApp for Work (2026)
Best for compliance-driven organizations — Mattermost gives IT teams full control over message data, making it the strongest choice when WhatsApp's data sovereignty gaps are the primary concern.
Slack Alternatives That Don't Destroy Deep Work (2026)
Best for DevOps and engineering teams that need Slack-like functionality with significantly better notification control and self-hosted data sovereignty.