# Mattermost

Mattermost is an open-source team messaging and collaboration platform rated 4.3/5 on G2 from 700+ reviews. Profile: pricing, self-hosted option, and how it compares to Slack.

**Category:** Open-source team messaging and collaboration platform  
**Vendor:** Mattermost, Inc.  
**Founded:** 2015  
**HQ:** Palo Alto, California, US  
**Website:** https://mattermost.com  


## About

Mattermost is a Palo Alto-based open-source team messaging platform founded in 2015 by Ian Tien and Corey Hulen. Built as a self-hosted alternative to Slack, Mattermost is particularly popular in government, defense, healthcare, and financial services where data sovereignty and on-premises deployment are required. The platform provides channels, direct messages, file sharing, search, integrations, and compliance features (audit logs, E2E encryption, eDiscovery). Mattermost raised $50M in Series B funding in 2019 and is used by organizations including the U.S. Department of Defense, Red Hat, and Samsung. The platform serves security-conscious organizations that need Slack-like functionality without sending data to Slack's cloud.

## Ratings

| Source | Score | Reviews |
|---|---|---|
| G2 | 4.3/5 | ~700 |
| Capterra | 4.3/5 | ~300 |

## Funding

$50M+

| Round | Amount | Date | Lead |
|---|---|---|---|
| Seed | $3.5M | 2017 | Redpoint Ventures |
| Series A | $20M | 2018 | Redpoint Ventures |
| Series B | $50M | 2019 | y37 Capital |

## Viability

Stable. Strong niche in regulated and security-sensitive industries. Open-source moat with government customer base is durable. Not a high-growth story but a reliable platform.

## Pricing

Mattermost self-hosted Team Edition is free with unlimited users. Professional: $10/user/month (advanced governance, integrations). Enterprise: custom pricing with advanced compliance features. For cloud-hosted: Professional starts at $10/user/month.

| Plan | Price | Best for |
|---|---|---|
| Team (self-hosted) | Free | Organizations that can manage own infrastructure |
| Professional | $10/user/mo | Advanced governance, SLA, integrations |
| Enterprise | Custom | Advanced compliance, E2E encryption, dedicated support |

## What reviewers say

_~1,000 G2 and Capterra reviews, 2025-2026_

**Praised:**
- Self-hosted deployment means your data never leaves your infrastructure
- U.S. DOD Authority to Operate (ATO) certification is unique in the category
- Compliance features (audit logs, E2E encryption, eDiscovery) are enterprise-grade
- Free self-hosted edition with unlimited users is genuinely valuable

**Complaints:**
- Less polished UX than Slack or Teams for everyday use
- Mobile apps are functional but not as smooth as Slack
- Setup and administration complexity is higher than Slack

## Compliance

- **SOC 2:** Yes (Type II)
- **GDPR:** Yes
- **HIPAA:** Yes (Enterprise)
- **SSO:** Yes (Professional+)

## Integrations

- GitLab
- GitHub
- Jira
- Confluence
- Zoom
- PagerDuty
- ServiceNow
- Splunk
- Jenkins
- Kubernetes
- Zapier

## FAQs

### Is Mattermost a good Slack replacement?

For security-conscious organizations that need self-hosted deployment, Mattermost is the best Slack alternative. For general commercial use, Slack has better UX, more app integrations, and is easier to administer. Mattermost wins when data sovereignty is non-negotiable.

### Is Mattermost HIPAA compliant?

Yes, with the Enterprise plan. Mattermost offers E2E encryption, audit logs, and BAA support for healthcare organizations.


## Sources

- [Mattermost website](https://mattermost.com): Product and pricing
- [G2 Mattermost reviews](https://www.g2.com/products/mattermost/reviews): User reviews