OPEN-SOURCE MIGRATION BENCHMARK License: MIT / AGPL-3.0 ★ 31.5k GitHub Stars

Replace Slack with Self-Hosted Mattermost

Enterprise-grade open-source team messaging, playbooks, and voice calls Stop paying Pro ($8.75/seat/mo) ($88/mo for a 10-person team) and run Mattermost on a $4.50/mo Linux VPS with full data sovereignty.

10-Seat Annual Savings

+$996 / yr

vs Slack standard plan

Container RAM & vCPU

1024 MB RAM

1.0 vCPU • Migration: Easy (Slack export ZIP importer)

Recommended Cloud Box

$4.50/mo VPS

Hetzner CX22 (4GB RAM / 2 vCPU)

1-to-100 Seat Total Cost of Ownership (TCO) Table

Comparing Slack (Pro ($8.75/seat/mo)) vs Mattermost on Hetzner CX22 (4GB RAM / 2 vCPU).

Team Size	Slack Cost	Mattermost VPS	Net Annual Savings
1 Seat (Solo)	$8.75/mo ($105/yr)	$4.50/mo (CX22)	+$51 / year
5 Seats	$43.75/mo ($525/yr)	$4.50/mo (CX22)	+$471 / year
10 Seats	$87.50/mo ($1,050/yr)	$4.50/mo (CX22)	+$996 / year
25 Seats	$218.75/mo ($2,625/yr)	$4.50/mo (CX22)	+$2,571 / year
50 Seats	$437.50/mo ($5,250/yr)	$4.50/mo (CX22)	+$5,196 / year
100 Seats	$875.00/mo ($10,500/yr)	$4.50/mo (CX22)	+$10,446 / year

Production Docker Compose + Caddy Auto-SSL

Copy and run docker compose up -d on any Ubuntu 24.04 server.

Open in Multi-Tool Builder →

# Production Docker Compose: Mattermost (Replaces Slack)
services:
  caddy:
    image: caddy:2-alpine
    restart: unless-stopped
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./Caddyfile:/etc/caddy/Caddyfile:ro
      - caddy_data:/data
    networks:
      - stack_net

  mattermost:
    image: mattermost/mattermost-team-edition:release-10
    container_name: stack-mattermost
    restart: unless-stopped
    environment:
      - "TZ=UTC"
      - "MM_SQLSETTINGS_DRIVERNAME=postgres"
      - "MM_SQLSETTINGS_DATASOURCE=postgres://postgres:${POSTGRES_PASSWORD:-strongpassword}@postgres:5432/mattermost?sslmode=disable"
      - "MM_SERVICESETTINGS_SITEURL=https://chat.${DOMAIN:-yourdomain.com}"
    volumes:
      - mattermost_data:/data
    networks:
      - stack_net

  postgres:
    image: pgvector/pgvector:pg16
    container_name: stack-postgres
    restart: unless-stopped
    environment:
      - "POSTGRES_USER=postgres"
      - "POSTGRES_PASSWORD=${POSTGRES_PASSWORD:-strongpassword}"
    volumes:
      - postgres_data:/var/lib/postgresql/data
    networks:
      - stack_net

networks:
  stack_net:
    driver: bridge

volumes:
  caddy_data:
  mattermost_data:
  postgres_data:

Caddyfile (Automatic HTTPS Reverse Proxy):

# Automatic Let's Encrypt HTTPS for Mattermost
mattermost.{$DOMAIN:yourdomain.com} {
  encode zstd gzip
  reverse_proxy mattermost:8065
}

Why Teams Switch to Mattermost

✓Slack-compatible webhooks & slash commands
✓Built-in voice calls & screen sharing
✓Unlimited searchable history forever

GitHub Repository mattermost/mattermost

Official Website mattermost.com

Docker Image mattermost/mattermost-team-edition:release-10

Database Needed PostgreSQL 16

1-Click Cloud VPS Hosting

Deploy Mattermost in 60 Seconds

Sized automatically for Mattermost (1024MB container RAM + OS overhead).

Hetzner Cloud (CX22)

Includes €20 Free Cloud Credit

$4.50/mo →

DigitalOcean Droplet

Includes $200 60-Day Free Credit

$24.00/mo →

Railway.app Managed Container

Zero server maintenance

$5.00/mo →

PRODUCTION BOILERPLATE ZIP

Get All 16 Pre-Built Production Stacks + Encrypted S3 Backups

Includes pre-tuned docker-compose.yml, Caddy Auto-SSL, AES-256 encrypted nightly S3/R2 Postgres backups, and Ubuntu 24.04 UFW/Fail2ban hardening scripts.

Other Open-Source Alternatives to Slack:

Compare Slack vs Zulip (★ 22.1k) →