Skip to content
ToolGPA

Slack alternatives · Team Chat

Open-source alternatives to Slack

Slack is not described as open source on its own site. 7 of the 33 other team communication apps in this directory are open source, according to their own sites.

Slack has a free plan. Paid plans start at $7.25 per user / month, billed annually. All of them are free or have a free plan.

7 tools · Listings checked up to Oct 6, 2026 · Where the facts come from

How each one differs from Slack

  1. Mattermost

    Self-hosted team messaging with playbooks, calls and boards

    • Mattermost is open source and self-hostable, according to its own site.
    • Mattermost also covers kanban boards and AI agents.
    • Slack also covers documents, video calls and file sharing.
    Mattermost vs SlackMattermost pricing and details

  2. Element

    End-to-end encrypted chat and calls on the Matrix standard

    • Element is open source, self-hostable and end-to-end encrypted, according to its own site.
    • Slack also covers workflow automation and documents.
    Element vs SlackElement pricing and details

  3. Rocket.Chat

    Open-source, self-managed chat for security-focused teams

    • Rocket.Chat is open source, self-hostable and end-to-end encrypted, according to its own site.
    • Slack also covers workflow automation, documents and video calls.
    Rocket.Chat pricing and details

  4. Zulip

    Open-source team chat that organizes channels by topic

    • Zulip starts at $3.50 per user / month self-hosted (billed monthly); Cloud from $6.67 billed annually. Slack starts at $7.25 per user / month, billed annually.
    • Zulip is open source and self-hostable, according to its own site.
    • Slack also covers workflow automation, documents and video calls.
    Zulip pricing and details

  5. Wire

    End-to-end encrypted messaging and calls for organizations

    • Wire starts at €7.45 per person / month, paid annually. Slack starts at $7.25 per user / month, billed annually.
    • Wire is open source, self-hostable and end-to-end encrypted, according to its own site.
    • Slack also covers workflow automation and documents.
    Wire pricing and details

  6. ONCE Campfire

    Self-hosted group chat from 37signals, free and open source

    • ONCE Campfire is free. Slack starts at $7.25 per user / month, billed annually.
    • Only Slack lists macOS, Windows, Linux, iOS and Android apps.
    • ONCE Campfire is open source and self-hostable, according to its own site.
    • Slack also covers workflow automation, documents and video calls.
    ONCE Campfire pricing and details

  7. Jitsi Meet

    Free, open-source video meetings you can self-host

    • Jitsi Meet is free. Slack starts at $7.25 per user / month, billed annually.
    • Jitsi Meet is open source, self-hostable and end-to-end encrypted, according to its own site.
    • Slack also covers workflow automation, documents, team chat and file sharing.
    Jitsi Meet pricing and details

Common questions

Is there an open-source alternative to Slack?

Yes. Mattermost, Element, Rocket.Chat, Zulip, Wire, ONCE Campfire and Jitsi Meet are open source, according to their own sites.

Is Slack open source?

Slack is not described as open source on its own site. The listing was checked on Oct 5, 2026 against the pages it cites.

When was this checked?

Each listing shows its own date. On this page they run from Oct 5, 2026 to Oct 6, 2026. Vendors change prices and plans without notice, so confirm on their site before you buy.

This page is built from the listings. A tool is here because its listing says so, and the order is how close each is to Slack: the alternatives its listing names first, then the tools that share the most features with it.