Open Source Self-Hosted Slack Alternatives

    Slack is not available as a self-hosted solution but there are plenty of alternatives for power users and business that want to host a solution on-premise. The best Self-Hosted alternative is Mattermost, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to Slack and many of them is available as a self-hosted solution so hopefully you can find a suitable replacement. Other interesting Self-Hosted alternatives to Slack are Element (Free Personal, Open Source), Zulip (Free Personal, Open Source), Rocket.Chat (Freemium, Open Source) and Matrix.org (Free, Open Source).

    This page was last updated Jun 11, 2021

    Platforms

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    • Online
    • Android
    • iPhone
    • Windows
    • Mac
    • iPad
    • Linux
    • Android Tablet
    • Software as a Service (SaaS)
    • Self-Hosted
    • Chrome OS
    • Windows Phone
    • Apple Watch
    • Google Chrome
    • BSD
    • Blackberry
    • Cloudron
    • Slack
    • Windows S
    • JavaScript

    Features

    • Team Collaboration
    • Group chat
    • Real time collaboration
    • Chat
    • Video chat
    • Task Management
    • Project management
    • File sharing
    • Integrated File Sharing
    • Messaging
    • Team chat
    • Video calling
    • Group collaboration
    • Encrypted chat
    • Voice Call
    • Team messaging
    • Team work
    • Share your screen
    • Video Conferencing
    • Voice chat

    License

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    • Free
    • Open Source
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    All Filters

    • Mattermost is an open source, self-hosted Slack alternative. View 122 alternatives to Mattermost
      Almost everyone thinks Mattermost is a great alternative to Slack.
      • FreemiumOpen Source
      • Mac
      • Windows
      • Linux
      • Android
      • iPhone
      • Android Tablet
      • iPad
      • Self-Hosted
      • JavaScript
      • Go (Programming Language)
      • Cloudron
      Mattermost vs Slack
      pros, cons and recent comments
       all • positive • negative      relevance • date
      shelehovchanin Same functionality. Same interface. At the same time, there are much fewer restrictions. IN my experience, the free version is great enough for a team of 100 people
      Top positive comment  about 2 years ago

      6
      Its the same but you keep your server where you want so no one is playing with your data, and you can have an unlimited history depending on what you need for free so really way better !
      Top positive comment  about 4 years ago

      3
      liger1978 Great interface, you control your data.
      Positive comment about 1 year ago

      -1
      It's faster for one thing. It's far superior in terms of data ownership, and it's extremely scalable.
      Positive comment about 1 year ago

      0
      svelle Has more flexibility due to its extensive plugin system compared to other alternatives.
      Positive comment about 1 year ago

      0
      Mudie Looks and works very much the same as Slack and complete control over your data housed separately from anyone else.
      Positive comment about 1 year ago

      0
      jaydeland Open source with control over your data.
      Positive comment about 1 year ago

      -3
      Show more comments
      7 of 19 comments
    • Element is a secure collaboration and messaging app based on the Matrix protocol. It’s decentralised to deliver digital sovereignty, and based on an open standard for easy connections and interoperability. It is end-to-end encrypted by default. View 244 alternatives to Element
      Almost everyone thinks Element is a great alternative to Slack.
      • Free PersonalOpen Source
      • Mac
      • Windows
      • Linux
      • Online
      • Android
      • iPhone
      • Android Tablet
      • iPad
      • Self-Hosted
      • Matrix.org
      • Cloudron
      Element vs Slack
      pros, cons and recent comments
       all • positive • negative      relevance • date
      brinerustle because its open source, decentralised, and end-to-end secure. Plus the folks at matrix.org are working to get us out of our communication silos by creating standards for communication interoperability!
      Top positive comment  over 3 years ago

      4
      Federated, free standard and free software
      Top positive comment  over 3 years ago

      3
      Privacy by design and based on matrix protocol!
      Positive comment 7 months ago

      0
      Federated, decentralized, encrypted, open-source.
      Positive comment almost 2 years ago

      3
      User6044478 Open Source / Free Software,
      Positive comment about 3 years ago

      0
      User6044478 decentralised, federated, end-to-end encrypted communication.
      Positive comment over 3 years ago

      7
      Free and opensource with better performance and features for team communication.
      Positive comment almost 4 years ago

      3
      Show more comments
      7 of 9 comments


    • Zulip is a group chat app in which messages are threaded by topic, helping you have long-running, organized conversations. View 230 alternatives to Zulip
      Almost everyone thinks Zulip is a great alternative to Slack.
      • Free PersonalOpen Source
      • Mac
      • Windows
      • Linux
      • Online
      • Android
      • iPhone
      • Android Tablet
      • BSD
      • iPad
      • Self-Hosted
      Zulip vs Slack
      pros, cons and recent comments
       all • positive • negative      relevance • date
      abijith Three reasons: 1. Open source. 2. Stream 3. Topics
      Top positive comment  over 3 years ago

      6
      Zulip is open source and the methods of communications used is vastly different. It is specially useful in professional environments where different teams might want to participate in different conversations at the same time. Zulip solves this problem by including topics, where in each channel/stream, multiple topics can exist at once, at the same time.
      Top positive comment  about 2 years ago

      3
      the threading model is the best i've used for keeping up with active communities, and the open-source community is excellent.
      Positive comment 7 months ago

      1
      It's a little different, for sure, but what it does, it does better than slack. Not a open source copy of slack like mattermost. If you want slack and nothing else, but in open source, stick to mattermost, if you want something that exceeds that, choose zulip.
      Positive comment 7 months ago

      1
      paulocoghi More than feature parity with Slack, it's better because of Streams and Topics. It offer the same free tier with 10.000 max messages and better paid plans to the hosted version, and also provide the open source self-hosted option to install it on your own server and also remove the max messages limits. 5 stars
      Positive comment over 1 year ago

      2
      The concept of topics to each message is a super useful feature :)
      Positive comment about 2 years ago

      2
      superbiche Open Source without limitations when on premises. Much better information categorisation with Streams & Topics. Vibrant community.
      Positive comment over 2 years ago

      3
      Show more comments
      7 of 16 comments
    • Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework. View 119 alternatives to Rocket.Chat
      Almost everyone thinks Rocket.Chat is a great alternative to Slack.
      • FreemiumOpen Source
      • Mac
      • Windows
      • Linux
      • Self-Hosted
      • Cloudron
      Rocket.Chat vs Slack
      pros, cons and recent comments
      JohnFastman Does everything Slack does AND it's open source. However, it's also self-hosted. This means you have to put in the effort to set it up, but you control your own data, which is a huge advantage to your privacy - your chats and files don't sit on someone else's servers, ready for them or hackers to look at.
      Positive comment over 4 years ago

      8
      Rocket.Chat comes very close to slack regarding it's core features and handling.
      Positive comment about 3 years ago

      4
      open source, locally hosted so you own your data.
      Positive comment over 2 years ago

      0
    • Matrix defines a set of open APIs for decentralised communication, suitable for securely publishing, persisting and subscribing to data over a global open federation of servers... View 121 alternatives to Matrix.org
      Most users think Matrix.org is a great alternative to Slack.
      No screenshots yet
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • Online
      • Android
      • iPhone
      • Android Tablet
      • iPad
      • Self-Hosted
      • WebRTC
      • Python
      • JavaScript
      • Go (Programming Language)
      • Cloudron
      • Java
      • Perl
      Matrix.org vs Slack
      pros, cons and recent comments
      It can be easily bridged to many other chat systems, including Slack, which makes transitioning *much* easier. It's also open source and decentralized (self-hostable + communication with other servers).
      Top positive comment  almost 4 years ago

      0
      Respects your Freedom. Increasingly popular
      Top positive comment  over 3 years ago

      0
      somegirlfromit Matrix is a protocol, not a client.
      Top negative comment  almost 2 years ago

      18
      User6044478 Open source, fecentralized, federation, chat-voice-video function.
      Positive comment over 3 years ago

      -1
      Free open source instant messaging service with federation.
      Positive comment almost 4 years ago

      -1
      free, end-to-end encryption
      Positive comment almost 4 years ago

      0
      nrg200 Capable of everything Slack can do, but can be self-hosted - keeping a team's data in-house.
      Positive comment almost 4 years ago

      -1


    • Wire is the most secure collaboration platform featuring messenger, voice, video, conference calls, file-sharing, and external collaboration –all protected by the most secure... View 256 alternatives to Wire
      Most users think Wire is a great alternative to Slack.
      • Free PersonalOpen Source
      • Mac
      • Windows
      • Linux
      • Online
      • Android
      • iPhone
      • Android Tablet
      • iPad
      • Self-Hosted
      • Software as a Service (SaaS)
    • Screensharing, online meetings & web conferencing without data leaks. Running over your own Nextcloud server. View 78 alternatives to Nextcloud Talk
      • Free PersonalOpen Source
      • Online
      • Android
      • iPhone
      • iPad
      • Self-Hosted
    • Corteza Messaging is a secure, high performance, open source Slack alternative that allows your teams to collaborate more efficiently, as well as communicate safely with other organisations or customers. View 46 alternatives to Corteza Messaging
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • Online
      • Android
      • iPhone
      • Android Tablet
      • iPad
      • Self-Hosted
    • The free and open-source Crust Messaging is a secure, high performance,Slack alternative that allows your teams to collaborate more efficiently, as well as communicate safely with other organisations or customers. View 36 alternatives to Crust Enterprise Messaging
    • Self-hosted chat for small teams. View 83 alternatives to Let's Chat

      Discontinued

      As stated at https://github.com/sdelements/lets-chat/issues/781 , the project is no longer developed since August 2017. Last version, 0.4.0, released in June 2015, can be still downloaded from GitHub together with the source code.

      • FreeOpen Source
      • Self-Hosted
    Showing 10 of 25 alternatives