Mattermost

Open source alternative to Slack, Microsoft Teams and Google Workspace

39.4K stars
Active this week
Last commit 1 day ago

Last verified Oct 20, 2026

Host team messaging with Mattermost, a self-hosted Slack alternative for channels, threads, integrations, and security-sensitive collaboration.

Visit website GitHub39.4K 1-click deploy on Hostinger

Read the full breakdownWho it is for, how it works, trade-offs and the FAQ

who it's for

Who Mattermost is for#

Security-sensitive engineering teams

Use Mattermost for incident rooms, deployment coordination, and operational chat where logs must stay on controlled infrastructure.

Skip if:

Skip if your team wants the lowest-maintenance hosted chat and has no data residency requirement.

IT teams building service desk workflows

Use channels, integrations, and automation to route internal support and infrastructure requests.

Skip if:

Skip if you need a full ticketing platform with SLA reporting as the primary system of record.

the problem

The problem it solves#

Cloud chat creates risk when incident discussions, customer data, or internal engineering decisions must stay inside controlled infrastructure. Vendor pricing and retention rules also decide how much history teams can keep and search.

how Mattermost solves it

How it solves it#

Self-hosted chat platform

Mattermost runs on your infrastructure as a Go and React application, with PostgreSQL as the backing database.

Software delivery workflows

The README calls out DevSecOps, incident resolution, and IT service desk use cases, making Mattermost more than a general chat room.

Messaging plus calls and automation

Mattermost combines channels, workflow automation, voice calling, screen sharing, and AI integration in one collaboration surface.

strengths · trade-offs

Strengths and trade-offs#

Strengths

Data control for regulated teamsSelf-hosting keeps messages and files under your own operational controls, which matters for defense, healthcare, finance, and critical infrastructure teams.
Familiar Slack-style workflowChannels, threads, integrations, and mobile apps reduce migration friction for teams moving from proprietary chat.

Trade-offs

-Open core packagingMattermost has a MIT-licensed core and paid enterprise features. Buyers should map required compliance, permissions, and support needs before assuming the free edition covers every requirement.

versus alternatives

Mattermost vs alternatives#

Mattermost vs Slack

Mattermost is the better choice when chat data residency, auditability, and self-hosting matter more than a fully managed SaaS experience. Slack is still easier for teams that prioritize third-party app breadth, low administration, and consumer-style onboarding.

tech stack · detected from GitHub

What it's built on#

Languages: GoJavaScriptTypeScript
Frameworks: ExpressReactReact Native
Databases: PostgreSQL
Tooling: Webpack

frequently asked

FAQ#

Is Mattermost self-hosted?

Yes. Mattermost is built for self-hosted deployment and also offers managed options.

What does Mattermost replace?

Mattermost commonly replaces Slack or Microsoft Teams for teams that need stronger deployment control.

What database does Mattermost use?

The README says Mattermost relies on PostgreSQL.

Looking for more

Other ways to replace Slack, Microsoft Teams and Google Workspace#

Buzz

Featuredfor Slack

Self-hosted team chat where people and AI agents work together

36,174Visit

Rocket.Chat

#2 in the Slack guide

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46,298

Zulip

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Async-first teams that need organized, low-noise conversations

26,085

Macro Chat

#4 in the Slack guide

Channels wired into the docs, tasks, and email around them

4,782

All 17 Slack alternatives 8 open source Slack alternatives, ranked

by category

Open source tools in these categories#

126

Hostinger

Run Mattermost on your own server

Hostinger sets Mattermost up as a one-click app on a VPS.

Deploy on Hostinger

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Who Mattermost is for#