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.

filter to find the best alternatives

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

Prav
A user-friendly messenger for everyone with a focus on privacy and freedom.
54 Prav alternatives
+5
License model
- Free • Open Source
Application types
- Instant Messenger
- Video Calling App
Platforms
- Android
- F-Droid
Prav Features
1. End-to-End Encryption
2. Privacy focused
3. Audio Calling
4. Text messaging
5. Supports XMPP
6. Xmpp
Show all NaN Prav features ▾
Prav VS Slack
Is Prav a good alternative to Slack?

Twake
Twake is a real-time teamwork platform. It is a suite of collaborative tools that includes the specificities of some bestsellers (Slack, Trello, Google Drive...). We provide professional messaging, storage space, online collaborative editors (Words, Excel, PowerPoint), task...
124 Twake alternatives
License model
- Freemium • Open Source
Application types
- Team Collaboration Tool
- Task Management Tool
Platforms
- Mac
- Windows
- Linux
- Self-Hosted
Twake Features
Real time collaboration
Workspaces
Show all NaN Twake features ▾
+2
Twake VS Slack
Is Twake a good alternative to Slack?
Comments about Twake as an Alternative to Slack

Guest
I like Twake as an alternative to Slack because it is open-source.
Positive comment •Feb 17, 2021
1
- Almost everyone thinks Twake is a great Slack alternative.
- Twake is Freemium and Open SourceSlack is Freemium and Proprietary

Dino
Dino is a modern open-source chat client for the desktop. It focuses on providing a clean and reliable Jabber/XMPP experience while having your privacy in mind. Using GTK+/Vala.
60 Dino alternatives
License model
- Free • Open Source
Application types
- Instant Messenger
- Group Chat App
Platforms
- Mac
- Linux
- BSD
Top Dino Features
1. End-to-End Encryption
2. OMEMO
3. Multiple Account support
4. Privacy focused
5. Federated
6. Community-based
7. Lightweight
8. Decentralized
9. OpenPGP
10. Ad-free
11. Real time collaboration
12. Xmpp
Show all NaN Dino features ▾
Dino VS Slack
Is Dino a good alternative to Slack?
Comments about Dino as an Alternative to Slack

Guest
Same user-friendliness of Slack, but running on the decentralized/federated XMPP network. No longer give your private/confidential data to a third-party.
Positive comment •Jun 4, 2019
1
- Most users think Dino is a great Slack alternative.
- Dino is Free and Open SourceSlack is Freemium and Proprietary
- Dino is Privacy focused, Lightweight and DecentralizedSlack is not according to our users

Nerimity
Nerimity is a modern and sleek chat app which includes features like free animated avatars & emojis, creating communities and posts, finding new communities to join, changing your username and tag for free and more!
21 Nerimity alternatives
License model
- Free • Open Source
Application types
- Instant Messenger
- Group Chat App
Platforms
- Windows
- Online
- Android
Nerimity Features
1. Ad-free
2. Privacy focused
3. Support for @mentions
4. VoiP Calls
5. No Tracking
6. Screen Sharing
7. Dark Mode
8. Lightweight
9. Cloud Sync
Show all NaN Nerimity features ▾
Nerimity VS Slack
Is Nerimity a good alternative to Slack?

Conduit Chat Server
Conduit is a simple, fast and reliable chat server powered by Matrix. Conduit is an alternative to Synapse and tries to be lightweight and easy to install, but it is still in development.
241 Conduit Chat Server alternatives
License model
- Free • Open Source
Application type
- Group Chat App
Platforms
- Online
- Self-Hosted
- Raspberry Pi
- Linux
- Debian
- Nix Package Manager
- Docker
- Docker Hub
Conduit Chat Server Features
1. Lightweight
2. Support for @mentions
3. Privacy focused
4. Rust
5. Matrix Protocol
6. Scalable
Show all NaN Conduit Chat Server features ▾
Conduit Chat Server VS Slack
Is Conduit Chat Server a good alternative to Slack?

Let's Chat
Self-hosted chat for small teams.
60 Let's Chat alternatives
License model
- Free • Open Source
Application type
- Team Collaboration Tool
Platforms
- Self-Hosted
Let's Chat Features
Web interface
Show all NaN Let's Chat features ▾
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.

Let's Chat VS Slack
Is Let's Chat a good alternative to Slack?

cabal
Experimental p2p community chat platform.
15 cabal alternatives
License model
- Free • Open Source
Application types
- Group Chat App
- Encrypted Chat App
Platforms
- Mac
- Windows
- Linux
- Self-Hosted
cabal Features
1. Command line interface
2. Works Offline
3. Decentralized
4. Text chat
5. Channels
6. Peer-To-Peer
7. Serverless
Show all NaN cabal features ▾
cabal VS Slack
Is cabal a good alternative to Slack?