15 Free and Open-source Self-hosted Messaging Platform And Slack Alternatives

15 Free and Open-source 
Self-hosted Messaging Platform And Slack Alternatives
Photo by Franck / Unsplash

Slack is a business-oriented messaging and project management platform for teams and enterprises. It has dozens of features and integration options that boost team productivity, enhance communication, and improve workflow.


However, its free version lacks many significant features as a full archive search, messages export, analytics and more.


Here, we provide you with a set of web-based open-source Slack alternatives that are also self-hosted, which means that you can download and install them on your server and have complete control over your data.

1- Mattermost

Mattermost is a free open-source self-hosted multi-user chat platform. It is written in Go and JavaScript (React). It supports 16 languages. It may not differ much from Slack, as it supports team, groups, creating multiple workspaces, attachments, and offers clients for Windows, Linux, and macOS.

Like Slack, Mattermost features hashtag support, channels, workspaces, threads, file and document attachments, and full-text search for messages.

However, as a self-hosted system that puts you in full-control of your data, and install, you can search all of your previous messages without a limit, which you can not do in Slack unless you are on the enterprise plan.

GitHub - mattermost/mattermost: Mattermost is an open source platform for secure collaboration across the entire software development lifecycle..
Mattermost is an open source platform for secure collaboration across the entire software development lifecycle.. - GitHub - mattermost/mattermost: Mattermost is an open source platform for secure…

2- RocketChat

RocketChat is another Slack alternative messaging platform that you can self-host at your server. It supports audio and video calls, file attachments, full-text search, and many other features.

RocketChat offers mobile and desktop clients alongside a web version which supports mobile as well.

Like Slack, Users can create groups, use hashtags in messages, pin and bookmark messages, and allows a high level customization.

RocketChat comes with a desktop clients, web self-hosted server/ client, and mobile apps.

It supports webhooks, embedded chat widget, and features a rich real-time API.

GitHub - RocketChat/Rocket.Chat: The communications platform that puts data protection first.
The communications platform that puts data protection first. - GitHub - RocketChat/Rocket.Chat: The communications platform that puts data protection first.

3- Nextcloud Talk

Nextcloud is an open-source self-hosted cloud platform for teams and groups. It has a vast ecosystem that contains apps anyone can install and run. Some of these apps offers a real-time chat and messages between users system users.

The chat module or apps allows an integration with other apps and modules such as file sharing, calendar, project management and more.

Many companies, teams, and communities prefer Nextcloud for their daily workflow to share files among their team members, adding the Nextcloud Messaging App can be a save.

Nextcloud
📱☁️💻 A safe home for all your data – community-driven, free & open source 👏 - Nextcloud

4- Zulip

Zulip is an open-source team collaboration tool with unique topic-based threading that combines the best of email and chat to make remote work productive and delightful. Fortune 500 companies, leading open source projects, and thousands of other organizations use Zulip every day.

Zulip is an open-source project that is released under the Apache-2.0 License.

It is an ideal solution for developer teams, game-dev communities, and companies of all size and sorts.

GitHub - zulip/zulip: Zulip server and web application. Open-source team chat that helps teams stay productive and focused.
Zulip server and web application. Open-source team chat that helps teams stay productive and focused. - GitHub - zulip/zulip: Zulip server and web application. Open-source team chat that helps team…

5- Tinode Instant Messaging Server

Tinode is an instant messaging server that you can self-host in your server. It is written in the Go programming language and released under the GPL-3.0 License.

It offers a client-side library, and clients for the web, desktop platforms, iOS and Android.

It is important to note that it is not XMPP/ Jabber server, it is more like Telegram.

GitHub - tinode/chat: Instant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots
Instant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots - GitHub - tinode/chat: Instant messaging platform. Backend in Go. Clients:…

6- Chatwoot

Chatwoot is an open-source, self-hosted customer engagement and messaging suite. Chatwoot lets you view and manage your customer data, communicate with them irrespective of which medium they use, and re-engage them based on their profile.

Chatwoot is an Open Source Self-hosted Customers Messaging System
Open-source customer engagement suite, an alternative to Intercom, Zendesk, Salesforce Service Cloud etc

7- Cabal

Cabal is an experimental chat and messaging platform that offers a similar client to slack.

Cabal is also a P2P decentralized platform. Its client works for Windows, Linux, and macOS.

GitHub - cabal-club/cabal-desktop: Desktop client for Cabal, the p2p/decentralized/local-first chat platform.
Desktop client for Cabal, the p2p/decentralized/local-first chat platform. - GitHub - cabal-club/cabal-desktop: Desktop client for Cabal, the p2p/decentralized/local-first chat platform.

8- Movim

Movim is a federated blogging and chat platform that acts as a web frontend for the XMPP protocol. It is released under the terms of the AGPLv3 license.

Movim offers a one-click install Chrome app, and a web app that works on all browsers including mobile ones.

GitHub - movim/movim: Movim - Decentralized social platform
Movim - Decentralized social platform. Contribute to movim/movim development by creating an account on GitHub.

9- Element

Element is an ideal alternative to Slack for anyone who value security and productivity. It is a group of apps built on top of the Matrix to offer a collaborative experience for Android, iOS, desktop and the web.

Element uses the Matrix.org ecosystem, it supports file attachments, voice recording, channels and workspaces, and voice/ video calls.

Element
We make Element, a decentralised encrypted comms app for the Matrix.org ecosystem - Element

10- Wire

Wire is an encrypted secure messaging platform for team and groups. It is a GDPR/ CCPA compliant.

Wire comes with a built-in end-to-end (E2EE) encryption and audio/ video collaboration support.

Wire is available for desktop (Windows, Linux, macOS), Android and iOS. If you prefer a web version, Wire team got you covered with a responsive web client.

Wire Swiss GmbH
Wire open source secure messenger. Wire Swiss GmbH has 286 repositories available. Follow their code on GitHub.

11- Relp

Relp is a free open-source self-hosted web messenger and file sharing app. It features push notification, offline-support, file transfer, and voice calls.

Relp is not a full-featured counterpart (alternative) to Slack, as it lacks many features that Slack has, however, it is a good alternative for small teams, community groups, families, and small companies.

Relp is an Open-source Self-hosted Slack Messenger Alternative
Relp - a web messenger. Enjoy free text chat, voice call, file sharing.
GitHub - vj-abishek/airdrop: Relp ✨ A web messenger. Enjoy free text chat and file sharing ✔
Relp ✨ A web messenger. Enjoy free text chat and file sharing ✔ - GitHub - vj-abishek/airdrop: Relp ✨ A web messenger. Enjoy free text chat and file sharing ✔

12- Nertivia

Nertivia Desktop is a free open-source desktop client for Nertivia network, which offers a similar and free features to slack. It supports creating servers, channels (workspaces), message emojis, file attachments, and themes.

Currently, the desktop client supports only Windows platform, but it is expected to support Linux and macOS in the near future.

GitHub - SupertigerDev/nertivia-desktop-app: Desktop app for https://nertivia.net
Desktop app for https://nertivia.net. Contribute to SupertigerDev/nertivia-desktop-app development by creating an account on GitHub.

13- Dino

Dino is a free open-source end-to-end messenger for Linux, but it can also be built from source for Windows and macOS.

By default, it supports end-to-end encryption via OMEMO or OpenPGP, with a full decentralized protocol.

Dino may lack some features like channels, workspace creation and hashtags. However, it is an ideal solution for small teams, and personal communication.

With Dino, users can upload documents, images, media files and many other file formats. Unlike Slack, messages search is unlimited, and users can use multiple accounts and group chat.

Secure your messaging with Dino: An End-to-End encryption chat client for Linux and macOS
Dino is a privacy-focused lightweight open-source messenger for Linux desktops. It supports end-to-end encryption out-of-the-box via OMEMO or OpenPGP encryption. In addition to its strong encryption, Dino allows the user to disable read and typing notification either globally or for specific con…
GitHub - dino/dino: Modern XMPP (“Jabber”) Chat Client using GTK+/Vala
Modern XMPP (“Jabber”) Chat Client using GTK+/Vala - GitHub - dino/dino: Modern XMPP (“Jabber”) Chat Client using GTK+/Vala

14- Revolt


Revolt is a fairly new open source user-first chat platform. You can find links to useful resources about the project below. It offers a desktop app, web port, several libraries, and a self-hosted port with Docker.

Revolt backend is built with Rust, which explains its robust performance.

Revolt
Open source user-first chat platform. Revolt has 36 repositories available. Follow their code on GitHub.

15- Threema

Threema is yet another free open-source secure messaging platform that uses WebRTC. It offers a web application, android, and iOS apps, that you can build and install.

Threema desktop is built on top of Electron.js which works for Windows, Linux, and macOS.

The project focuses on privacy and to be a GDPR-compliant. It can be self-hosted and customized to work on a local build apps.

Threema GmbH
Seriously Secure Messaging. Threema GmbH has 15 repositories available. Follow their code on GitHub.

Final thought

Slack is a great hosted platform for teams, but as it lacks many options for its free version, it is an essential to find a self-hosted open-source alternative. As we listed, the best free/ open source massagers and chat platforms, we hope that we offered with enough many options to pick up the one that fits your workflow.

If you know of any other open source free self-hosted platform, that we did not mention here, let us know.

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