Mattermost Review 2026
by Mattermost Inc.
Self-hosted, open-source team messaging built for high-security environments.
Starting Price
Free
Pricing Model
open-source
Free Tier
Yes
Category
Team Chat
Overview
Mattermost is designed for organizations in defense, government, and regulated industries that cannot use SaaS chat. It is fully open-source, air-gap deployable, and meets the strictest data sovereignty requirements.
Pros
- ✓Air-gap deployable for high-security environments
- ✓Fully open-source
- ✓Strong compliance certifications
Cons
- ✗Self-hosting demands significant IT resources
- ✗Less polished UX than Slack
- ✗Integrations require more configuration
Key Features
- Self-hosted deployment
- Channels and DMs
- Playbooks (incident response)
- Compliance exports
- Air-gap support
Pricing
Free (self-hosted, open-source). Professional from $10/user/mo. Enterprise pricing on request.
Check current pricing on Mattermost →Who is Mattermost for?
Government, defense, and regulated-industry teams requiring on-premise, air-gapped deployment
Frequently Asked Questions
Is Mattermost free?
Yes, Mattermost offers a free tier. Paid plans start at $0/mo.
How much does Mattermost cost?
Mattermost starts at $0/mo, with a free tier available. Free (self-hosted, open-source). Professional from $10/user/mo. Enterprise pricing on request.
What is Mattermost used for?
Self-hosted, open-source team messaging built for high-security environments. Government, defense, and regulated-industry teams requiring on-premise, air-gapped deployment
Is Mattermost worth it?
Mattermost's main strengths are air-gap deployable for high-security environments and fully open-source. The main drawback is self-hosting demands significant it resources.
What are the best alternatives to Mattermost?
There are several strong alternatives to Mattermost in the Team Communication category. See our full comparison on the Mattermost alternatives page for a ranked list.