Mattermost — An open-core, self-hostable team chat and workflow platform for organizations needing data sovereignty, used by NASA, Samsung, and government agencies.
By Noahlast updated pricing verified
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Mattermost in 20 seconds
Best for: regulated, government, or defense organizations needing self-hosted or air-gapped team chat with compliance controls
Pricing: Free self-hosted MIT core; Professional, Enterprise, and Enterprise Advanced all require contacting sales for a quote.
- Mattermost's core is MIT-licensed, self-hostable, and released monthly.
- Mattermost's GitHub repository has nearly 39,000 stars.
- Professional, Enterprise, and Enterprise Advanced tiers are sold only as prepaid annual seat-based subscriptions with no published flat pricing.
- Enterprise Advanced supports up to 200,000 concurrent users with air-gapped deployment and mobile biometrics.
- Mattermost is used by organizations including the U.S. Air Force, NASA, and Samsung.
Limitations: No paid tier publishes flat per-user pricing; all require a sales conversation.; Self-hosting the free core requires ongoing server maintenance.; Smaller integration ecosystem than Slack.
Top alternatives: Slack, Microsoft Teams, Rocket.Chat, Zulip, Element — full list
What is Mattermost?
Mattermost is a messaging and workflow platform built around deployment flexibility: its core (channels, threaded messaging, file sharing, audio/screenshare, playbooks) is released monthly under an MIT license and can be self-hosted on-premise, in a private cloud, or fully air-gapped, while advanced features sit behind a separate commercial "Enterprise" license, making it an open-core rather than fully open-source product. The platform's positioning has shifted toward "mission critical" and sovereignty use cases: it markets attribute-based access controls, data classification banners, audit trails, FIPS 140-3 and STIG-hardened compliance options, and sovereign AI agents for triage and summarization, aimed at government, defense, and critical-infrastructure customers who cannot use a standard SaaS chat tool for compliance reasons. It also includes more conventional team-chat features like threaded channels, playbook automation, Kanban-style task boards, and interoperability with Microsoft Teams. Mattermost is used by organizations including the U.S. Air Force, NASA, Samsung, and various European government agencies, alongside smaller engineering teams that self-host the free core for a Slack-like experience without vendor lock-in. Paid tiers (Professional, Enterprise, Enterprise Advanced) are sold as prepaid annual seat-based subscriptions with no published flat pricing; all require contacting sales for a quote.
Mattermost is a team collaboration and messaging platform built for organizations that need to control where their data lives, offering a free, MIT-licensed self-hosted core alongside paid Professional, Enterprise, and Enterprise Advanced tiers with added compliance, AI, and workflow-automation features. It's positioned for regulated industries, government, and defense sectors that need on-premise, air-gapped, or sovereign-cloud deployment rather than a purely SaaS chat tool, and is used by organizations including the U.S. Air Force, NASA, and Samsung. None of the paid tiers publish flat per-user pricing on-site; Professional, Enterprise, and Enterprise Advanced are all quoted as prepaid annual seat-based subscriptions available only through Mattermost sales. Its GitHub repository has nearly 39,000 stars, and the core is released monthly under an MIT license, while enterprise features (advanced compliance, sovereign AI, high availability) sit behind a separate commercial license.
Standout feature: Deployment flexibility for compliance-sensitive organizations: the same platform can run fully air-gapped or in a sovereign cloud with FIPS 140-3/STIG-hardened compliance options, not available from mainstream SaaS chat tools.
Biggest weakness: No paid tier publishes flat per-user pricing; Professional, Enterprise, and Enterprise Advanced all require a sales conversation and prepaid annual seat commitment, making it harder to budget or compare cost against competitors up front, and self-hosting the free core requires ongoing server maintenance.
Pros
- Self-hosted core is free (MIT-licensed) with no user limit, avoiding SaaS vendor lock-in.
- Deployment options (on-premise, private cloud, air-gapped) support compliance needs that pure-SaaS chat tools can't meet.
- Native apps across web, Windows, macOS, Linux, iOS, and Android.
- Open-core model means the underlying chat engine's code is auditable even though advanced features are commercially licensed.
Cons
- No published flat pricing for any paid tier; all require contacting sales and a prepaid annual commitment.
- Self-hosting the free core requires ongoing server maintenance, scaling, and upgrades.
- Advanced features (sovereign AI, high availability, air-gapped support) sit behind the commercial Enterprise license, not the open-source core.
- Smaller third-party app/integration ecosystem than Slack, which has a much larger app marketplace.
Mattermost pricing
Free · verified from the vendor's pricing page
| Plan | Price | Notes |
|---|---|---|
| Free (self-hosted core) | Free | MIT-licensed core, self-hosted, released monthly. Includes channel messaging, file sharing, 1:1 audio/screenshare, threaded discussions, and basic search. Intended for technical evaluation and self-managed deployments; support is community-only. |
| Professional | Custom | Contact sales; prepaid annual seat-based subscription, up to 250 users. Adds custom branding/themes, search up to 3M posts, and Professional support (business hours, next-business-day response). |
| Enterprise | Custom | Contact sales; prepaid annual seat-based subscription, up to 50,000 concurrent users. Adds sovereign AI summarization, playbook workflow dashboards, Microsoft Teams interoperability, FIPS 140-3/STIG compliance, high-availability clustering, and 24x7 support. |
| Enterprise Advanced | Custom | Contact sales; prepaid annual seat-based subscription, up to 200,000 concurrent users. Adds mobile biometrics, data-at-rest encryption, air-gapped deployment support, attribute-based access controls, and burn-on-read messages. |
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