Mattermost

Open-source alternative to Slack and Microsoft Teams. Self-hosted team collaboration designed for operational and technical organizations.

A practical Slack replacement for teams with compliance or on-premises requirements.

At a glance

ReplacesSlack, Microsoft Teams
Open-source licenseAGPL-3.0 / open core
PrivacyOn-premises deployment keeps sensitive team data under organizational control.
Lightweight signalCan consolidate chat and incident workflows in one controlled service.
Community healthLarge company-backed project
PlatformsWeb, Windows, macOS, Linux, Android, iOS
Privacy advantage

On-premises deployment keeps sensitive team data under organizational control.

Less bloat

Can consolidate chat and incident workflows in one controlled service.

Trust signal

Large company-backed project. Verify current releases and open issues in the source repository before critical deployment.

Should you switch to Mattermost?

A practical Slack replacement for teams with compliance or on-premises requirements. A successful migration starts with a small real project, not a feature checklist. Test the files, integrations, shortcuts, and collaboration steps you use every week before removing the existing tool.

Open source gives you inspectable code and a path away from vendor lock-in, but it does not eliminate tradeoffs. Support may be community-led, some commercial file formats may be imperfect, and self-hosted options require security updates and backups. Use the official website and source repository above to confirm current compatibility.

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