Mattermost at a glance
Checked 15 Oct 2026Mattermost is a mature open core Slack alternative (Go and React, PostgreSQL). Two free routes: the MIT-licensed Team Edition, aimed at teams under 250 users and losing SSO since 2025; or the Enterprise build run free as "Entry", which caps viewable history at 10,000 channel messages and suits under 50 users. Compliance, high availability and support are paid. Up to 1,000 users need about 1 vCPU and 2 GB RAM. Desktop and mobile apps exist. The server runs on Linux or in Docker, not natively on Windows.
Cite this page
RepoQuarry. “Mattermost.” Checked 15 Oct 2026. https://repoquarry.dev/projects/mattermostHow much of Slack does it replace?
5 of 5 jobs. Covers core Slack work; free editions have user, history (Entry) and SSO (Team Edition) limits. Feature parity not checked.
Partial: Channels and direct messages Partial replacement
Partial: Threaded conversations Partial replacement
Partial: Voice and video huddles Partial replacement
Partial: Integrations Partial replacement
Partial: Search and message history Partial replacement
Facts, with sources
Every answer links to where we found it. We read the documentation; we did not install it.
QuestionAnswerSourceChecked
Runs on my machine? Confirmed: Self-hosted server (Docker, Linux package or tarball) or Mattermost Cloud
Deploy a Mattermost Self-hosted instance in minutes via Docker, Ubuntu, or tar.github.com · mattermost#readme ↗ 1d ago
Code licence Partial: Source under AGPL-3.0 (or commercial licence); Mattermost-built binaries under MIT; admin tools and config under Apache-2.0
You are licensed to use compiled versions of the Mattermost platform produced by Mattermost, Inc. under an MIT LICENSEgithub.com · LICENSE.txt ↗ 1d ago
Commercial use Partial: Yes; Team Edition (MIT binary) is advised for under 250 users, Entry has history and other limits; AGPL applies to modified builds; trademark needs approval
Team Edition is intended for small teams, hobbyists, or personal use under 250 activated users where single sign-on (SSO) is not required.docs.mattermost.com · editions-and-offerings.html ↗ 1d ago
Paid services needed? Partial: None required; paid subscriptions add SSO (beyond Entry), compliance, high availability, full history and support
10,000 Channel messages history across all channels (older messages remain in the database but aren't viewable or searchable)docs.mattermost.com · editions-and-offerings.html ↗ 1d ago
Hardware Confirmed: 1 vCPU and 2 GB RAM for up to 1,000 users; 2 vCPU and 4 GB RAM for 1,000-2,000; PostgreSQL 14+
1 - 1,000 users - 1 vCPU/cores, 2 GB RAMdocs.mattermost.com · software-hardware-requirements.html ↗ 1d ago
Operating systems Confirmed: Server on Linux (Ubuntu, Debian, RHEL 9) or Docker; desktop apps for Windows 11+, macOS 14+, Ubuntu; iOS and Android apps
Using the Mattermost Docker deployment on a Docker-compatible operating system (Linux-based OS) is still recommended.docs.mattermost.com · software-hardware-requirements.html ↗ 1d ago
Setup effort Confirmed: Medium; Docker Compose, Ubuntu package, tarball or Kubernetes, plus PostgreSQL
Deploy a Mattermost Self-hosted instance in minutes via Docker, Ubuntu, or tar.github.com · mattermost#readme ↗ 1d ago