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Migration guide

Migrate from SlackMattermost

Easy4-8 hours5 steps
Why migrate

Escape Slack's 90-day message retention on free plan, get full message history, self-host for compliance, avoid per-user fees.

Step-by-step

  1. 1

    1. Export Slack workspace

    In Slack: Settings → Import/Export → Export. Wait for the email with your full ZIP export.

  2. 2

    2. Install Mattermost

    Run via Docker: `docker-compose up -d` using the official Mattermost compose file.

  3. 3

    3. Use Mattermost's built-in Slack importer

    Mattermost ships with `mmctl import slack` — drop in your Slack ZIP. Channels, messages, users, attachments all transfer.

  4. 4

    4. Migrate integrations

    Slack apps don't auto-port. Set up Mattermost webhooks/plugins for the integrations you actually use.

  5. 5

    5. Update DNS + invite users

    Point a subdomain at Mattermost, send invite links to your team.

Gotchas to watch

  • Threaded messages import correctly. Pinned messages may not.
  • Slack workflows / apps don't auto-port — rebuild as Mattermost plugins.
  • User profile photos transfer but you may need to re-upload some.

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More migration guides

Migrate from Slack to Mattermost — Step-by-Step Guide (2026) — StackPicks — StackPicks