Open Source Slack Alternatives

The best open source alternative to Slack is Mattermost. If that doesn't suit you, our users have ranked more than 100 alternatives to Slack and loads of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Slack are Element, Zulip, Rocket.Chat and Matrix.org.

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Slack alternatives are mainly Instant Messengers but may also be Group Chat Apps or Video Calling Apps. Other popular filters includes Self-Hosted + Open Source. Filter by these or use the filter bar below if you want a narrower list of alternatives or looking for a specific functionality of Slack.

Slack

851

Group Chat App
Freemium • Proprietary

Facilitates teams' real-time collaboration with versatile chat interface and advanced search in configurable channels across multiple platforms.

More about Slack

Slack alternatives page was last updated Sep 18, 2024

Kahla
Kahla is a free and open-source, cross-platform business messaging tool that supports end-to-end encrypted message communication and automatic destruction of messages.
16 Kahla alternatives
License model
- Free • Open Source
Application types
- Group Chat App
- Team Collaboration Tool
Platforms
- Mac
- Windows
- Linux
- Online
- Android
- Chrome OS
- Android Tablet
- Self-Hosted
Kahla VS Slack
Is Kahla a good alternative to Slack?

Hack Chat
hack.chat is a minimal, distraction-free chat application. Channels are created and joined by going to https://hack.chat/?your-channel. There are no channel lists, so a secret channel name can be used for private discussions.

Source code : [https://github.com/hack-chat/mai...
42 Hack Chat alternatives
License model
- Free • Open Source
Platforms
- Online
- Android
- Self-Hosted
Hack Chat Features
Distraction-free
Show all NaN Hack Chat features ▾
Hack Chat VS Slack
Is Hack Chat a good alternative to Slack?

dirc
Dirc is a peer-to-peer web application which uses WebRTC to set up connections between chat participants without requiring a back-end server. The static files can be self-hosted. Other features:
42 dirc alternatives
License model
- Free • Open Source
Application types
- Group Chat App
- Team Collaboration Tool
Platforms
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Chrome OS
- Self-Hosted
dirc Features
No registration required
IRC
Show all NaN dirc features ▾
dirc VS Slack
Is dirc a good alternative to Slack?

Databag
A tiny self-hosted federated messenger for the decentralized web.
8 Databag alternatives
License model
- Free • Open Source
Application types
- Instant Messenger
- Group Chat App
Platforms
- Android
- iPhone
- Android Tablet
- iPad
- Self-Hosted
- F-Droid
Databag Features
1. Lightweight
2. End-to-End Encryption
3. Privacy focused
4. Ad-free
5. Decentralized
6. No Tracking
7. AES-256 Encryption
8. VoiP Calls
9. Federated
Show all NaN Databag features ▾
Databag VS Slack
Is Databag a good alternative to Slack?

Librem Chat
End-to-end encrypted chat, VOIP, and video calling used by millions of people.
173 Librem Chat alternatives
+1
License model
- Free • Open Source
Application types
- Group Chat App
- Encrypted Chat App
Platforms
- Android
- iPhone
- Android Tablet
- iPad
- F-Droid
Librem Chat Features
VoiP Calls
End-to-End Encryption
Decentralized
Ad-free
Show all NaN Librem Chat features ▾
Discontinued
App hasn't been updated on Play Store since 2020.

Librem Chat VS Slack
Is Librem Chat a good alternative to Slack?

eXo Platform
eXo Platform is an all-in-one digital workplace solution that helps you connect, align and engage your teams around a single interface. You can use it to improve company and peer-to-peer communication, boost collaboration and manage company knowledge.
95 eXo Platform alternatives
License model
- Free • Open Source
Application types
- Team Collaboration Tool
- Project Management Tool
Platforms
- Online
- Android
- iPhone
- Android Tablet
- iPad
- Self-Hosted
- Software as a Service (SaaS)
+5
Top eXo Platform Features
1. Project Management
2. Team Collaboration
3. Document Management
4. Real time collaboration
5. Gamification
6. Full-Text Search
7. Goal Tracking
8. Recurring Tasks
9. Reminders
10. Shared Folders
11. Calendar View
12. Two-factor Authentication
Show all NaN eXo Platform features ▾
eXo Platform VS Slack
Is eXo Platform a good alternative to Slack?

ZeroChat
An IRC-like internet chatroom hosted on ZeroNet, a distributed network. 0rc is a fully distributed website, and messages are shared through peers using the ZeroNet stack. In addition, making a new chatroom website is a simple as downloading the files and cloning the site.
90 ZeroChat alternatives
License model
- Free • Open Source
Platforms
- Mac
- Windows
- Linux
- Online
- Self-Hosted
- Python
- JavaScript
- ZeroNet
ZeroChat Features
Decentralized
Distributed
Show all NaN ZeroChat features ▾
Discontinued
Last update on github made over 5 years (March 13, 2016).

ZeroChat VS Slack
Is ZeroChat a good alternative to Slack?