Mattermost is an open source team collaboration platform that provides Slack-style messaging, file sharing, and workflow automation on infrastructure you control, built for teams in defense, healthcare, finance, and critical infrastructure who cannot use third-party cloud chat services.
The Problem
Slack and Microsoft Teams process your organization's communications on vendor servers, creating compliance risk for teams in regulated industries. Security teams, government contractors, and healthcare organizations often operate under policies that forbid uploading internal communications to external clouds. Even outside regulated industries, vendor-controlled chat means your message archive, integrations, and search history disappear the moment you stop paying.
How Mattermost Solves It
Mattermost runs on your own server, keeping all messages, files, and channel data on infrastructure you own and audit. The platform mirrors Slack's channel and thread model, supports persistent search and compliance exports, and offers webhooks and a plugin system for workflow automation. Teams connect via browser, desktop, and mobile apps. MIT licensed for the core platform; deploy via Docker, Kubernetes, or managed Kubernetes.
Key Features
- Full message archive on your own server: no third-party cloud access to communications
- Channels and threads: organized conversation structure with persistent search
- Compliance exports: audit-ready message exports for regulatory requirements
- Webhooks and bot framework: integrate with CI/CD pipelines, monitoring systems, and internal tools
- Mobile apps for iOS and Android with push notifications via your own proxy
- MIT licensed core; on-premises or cloud deployment with Kubernetes support
Who It's For
Mattermost is best for engineering teams and security-sensitive organizations in defense, finance, and healthcare that need self-hosted team messaging with compliance features. It suits DevOps and platform teams who want chat deeply integrated with their deployment pipelines and incident workflows.
Compared to Slack
Unlike Slack, Mattermost is fully self-hostable so no messages or files ever reach a third-party server. Slack has a smoother user experience, a larger third-party app directory, and faster mobile performance; Mattermost gives complete data sovereignty and fits regulated environments where Slack is not approved.
