# Mattermost

**Source:** https://geo.sig.ai/brands/mattermost  
**Vertical:** Productivity & Collaboration  
**Subcategory:** General  
**Tier:** Emerging  
**Website:** mattermost.com  
**Last Updated:** 2026-04-14

## Summary

Open-source team messaging platform for air-gapped and self-hosted enterprise deployments; trusted by defense, intelligence, and regulated industries.

## Company Overview

Mattermost is an open-source, self-hostable team messaging and collaboration platform built for security-conscious enterprises, government agencies, and development teams that cannot or will not use cloud-only solutions like Slack or Microsoft Teams. Founded in 2015 and headquartered in Palo Alto, Mattermost provides a Slack-like interface with channels, threads, file sharing, and integrations — but deployed entirely within an organization's own infrastructure or private cloud.

The company raised $50 million in Series B funding in 2019, backed by Redpoint, S28 Capital, and others, and has grown its customer base primarily in defense, intelligence, financial services, and regulated industries where data sovereignty and air-gapped deployment are requirements. Mattermost's open-source community edition has accumulated millions of downloads, while enterprise licenses fund ongoing development. By 2024-2025, the company serves major US defense contractors, NATO agencies, and large financial institutions.

In 2025, Mattermost has differentiated further by building AI-powered workflows directly into its platform — integrating with self-hosted LLMs (Llama, Mistral) to provide AI assistance that never sends data to external servers. This AI strategy directly addresses the compliance concerns preventing enterprises from using cloud-based AI tools. Mattermost competes with Slack, Teams, and Element (Matrix-based) but occupies a premium position for organizations with strict sovereignty requirements. The company's 2025-2026 focus includes expanded DevSecOps integrations and certifications for US federal procurement.

## Frequently Asked Questions

### What is Mattermost?
Mattermost is an open-source Slack alternative that provides secure collaboration for high-security enterprises, government agencies, and technical teams. It offers self-hosted and private cloud deployment options for organizations that prioritize security and data control.

### What products and services does Mattermost offer?
Mattermost offers secure team messaging, self-hosted collaboration, DevOps integrations, compliance workflows, and private cloud deployment options. These solutions are designed to meet the stringent security and compliance requirements of enterprise and government organizations.

### Who is Mattermost designed for?
Mattermost is designed for high-security enterprises, government agencies, and technical teams. It specifically serves industries like government, healthcare, and financial services that require stringent security and compliance standards.

### When was Mattermost founded?
Mattermost was founded in 2016. The company participated in Y Combinator's S12 batch.

### Where is Mattermost headquartered?
Mattermost is based in Palo Alto, California.

### How much funding has Mattermost raised?
Mattermost has raised a total of $70M in funding. The company's Series B round was $50M led by YC Continuity, which was the largest YC Series B investment at the time, with participation from Battery Ventures and Redpoint.

### What notable achievements has Mattermost earned?
Mattermost was ranked #1 'Most Loved' Slack alternative on Stack Overflow in 2022. The company has also successfully secured the largest Series B investment from Y Combinator Continuity.

### What makes Mattermost's approach different from other collaboration tools?
Mattermost is open-source and offers self-hosted and private cloud deployment options, giving organizations full control over their data. This approach prioritizes security and compliance, making it suitable for high-security environments that cannot use standard cloud-based collaboration tools.

### How can I get started with Mattermost?
Information about getting started with Mattermost was not provided in the company details.

### What are Mattermost's most recent developments?
Mattermost recently closed a $50M Series B funding round led by YC Continuity, the largest Series B investment from Y Combinator. The company was also ranked #1 'Most Loved' Slack alternative on Stack Overflow in 2022.

## Tags

b2b, collaboration, enterprise, messaging, open-source, productivity, saas, startup

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*Data from geo.sig.ai Brand Intelligence Database. Updated 2026-04-14.*