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

monocles chat
monocles chat is a fork of blabber.im and Conversations with some changes, to improve usability.
46 monocles chat alternatives
+5
License model
- Freemium • Open Source
Application types
- Instant Messenger
- Video Calling App
Platforms
- Online
- Android
- F-Droid
monocles chat Features
1. Dark Mode
2. End-to-End Encryption
3. VoiP Calls
4. Decentralized
5. Privacy focused
6. Ad-free
7. No Tracking
8. Voice Chat
Show all NaN monocles chat features ▾
monocles chat VS Slack
Is monocles chat a good alternative to Slack?

STAGE by vr-on
STAGE Cloud enables Unreal and Unity Enterprise professionals to instantly create, deploy and use their multi-user VR applications. STAGE Cloud requires only 3 simple steps to roll out multi-user VR applications. Further details: www.vr-on.cloud.
27 STAGE by vr-on alternatives
License model
- Freemium • Open Source
Application types
- Video Calling App
- Instant Messenger
Platforms
- Windows
- HTC Vive
- Unity
- Software as a Service (SaaS)
- Oculus Rift
STAGE by vr-on Features
1. Real time collaboration
2. Screen Sharing
3. VoiP Calls
4. End-to-End Encryption
5. Unreal Engine Integration
6. Multiuser mode support
7. Interactive Whiteboard
8. Group Voice Chat
9. Video Conferencing
Show all NaN STAGE by vr-on features ▾
STAGE by vr-on VS Slack
Is STAGE by vr-on a good alternative to Slack?

Modular.im
Awesome hosting for Matrix chat and integrations - built on the Matrix open ecosystem for secure, decentralised communication, by the creators of Matrix.
11 Modular.im alternatives
License model
- Paid • Open Source
Application types
- Video Calling App
- Encrypted Chat App
Platforms
- Online
- Self-Hosted
Modular.im Features
1. VoiP Calls
2. Support for MarkDown
3. DRM Free
4. Decentralized
5. Community-based
6. File Sending
7. Custom widgets
8. IRC
9. Server side history
10. Matrix Protocol
Show all NaN Modular.im features ▾
Modular.im VS Slack
Is Modular.im a good alternative to Slack?

Valour
Valour is an open-source, privacy focused alternative to platforms like Discord or Slack, developed by a small team of volunteers. The app has been in development for over three years and is currently in it's alpha stages of testing.
11 Valour alternatives
License model
- Free • Open Source
Platforms
- Online
Valour Features
1. Support for @mentions
2. Self Destructing Messages
3. Visual Pinboard
4. Privacy focused
5. No Tracking
6. VoiP Calls
7. Web-Based
Show all NaN Valour features ▾
Valour VS Slack
Is Valour a good alternative to Slack?

Cowork
Cowork is a free, gamified productivity app and virtual coworking space. It's built with task management features for students, colleagues, and freelancers. Users can create and customize shared coworking spaces for groups of people to work on their tasks together in and...
14 Cowork alternatives
License model
- Freemium • Open Source
Application types
- Team Collaboration Tool
- Task Management Tool
Platforms
- Online
- Software as a Service (SaaS)
Cowork Features
Gamification
Pomodoro Timer
Stay Focused
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Discontinued
Last commit is from May 2022

Cowork VS Slack
Is Cowork a good alternative to Slack?

qTeams
The future of Team collaboration. Secure. Cross platform. Manage Teams, Groups, Private & Public Channels. Invite. Meet. Work. Automate with over 700'000 Apps. Built-in Webinar & Webmeetings. Available as PrivateCloud or On Premise. Decentralized.
36 qTeams alternatives
License model
- Paid • Open Source
Application types
- Group Chat App
- Web Conferencing Tool
Platforms
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Android Tablet
- iPad
- Self-Hosted
- Software as a Service (SaaS)
+7
qTeams Features
1. Screen Sharing
2. Gitlab integration
3. GitHub Integration
4. Team work
5. LDAP support
6. Video Conferencing
7. Audio Conferencing
8. Webinar
Show all NaN qTeams features ▾
qTeams VS Slack
Is qTeams a good alternative to Slack?

Stork IM
Open Source Android XMPP Client.
21 Stork IM alternatives
License model
- Free • Open Source
Application types
- Instant Messenger
- Group Chat App
Platforms
- Android
Stork IM Features
1. Privacy focused
2. End-to-End Encryption
3. Decentralized
4. Ad-free
5. OMEMO
6. Xmpp
7. Private messaging
Show all NaN Stork IM features ▾
Stork IM VS Slack
Is Stork IM a good alternative to Slack?