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View detailsMattermost
An open-source team messaging platform that can be self-hosted for secure collaboration.
Mattermost is an open-source team messaging platform, similar to Slack but self-hosted. Teams run it on their own servers, which gives them full control over data, security, and compliance, and it is popular with government, defence, and regulated industries.
Key Features
- Open-source team messaging, self-hosted
- Channels, DMs, file sharing, and calls
- Full control over data and security
- Plugins and integrations
- Enterprise compliance and high availability
- Free to self-host
Pricing
| Plan | Price | Details |
|---|---|---|
| Pricing | Check official site | See the official site for current plans. |
Prices as listed in 2026 research. Always check the official site for the latest price — plans change. Free plan: Yes — it has a free plan.
Best for: organisations that need Slack-style messaging on their own servers for security or compliance.
Popular with: Business Owners, Developers
Popular with: Business Owners, Developers
How it works
The platform covers channels, direct messages, file sharing, video calls, and integrations, with a plugin system for extending it. It supports large deployments and offers enterprise features such as advanced compliance, high availability, and dedicated support.
Mattermost is free and open source to self-host, with paid enterprise plans for advanced features. It suits organisations that need Slack-style messaging but cannot put their data in a third-party cloud.
Pros and Cons
✓ Pros
- Free and open source to self-host
- Data stays under your control
- Good for regulated industries
- Slack-like experience
✗ Cons
- Self-hosting needs operations effort
- Smaller app ecosystem than Slack
- Enterprise features cost extra
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View detailsLast reviewed: November 2026