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

Threema
Threema is a new mobile messaging app that puts security first. With true end-to-end encryption, you can rest assured that only you and the intended recipient can read your messages.
113 Threema alternatives
+5
License model
- Paid • Open Source
Application types
- Instant Messenger
- Video Calling App
Platforms
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Android Tablet
- HUAWEI AppGallery
- iPad
Top Threema Features
1. End-to-End Encryption
2. Privacy focused
3. Encrypted Chat
4. Security focused
5. Integrated File Sharing
6. Ad-free
7. Cloud Sync
8. No Tracking
9. Encrypted Backup
10. Dark Mode
11. Multiple Account support
12. Two-factor Authentication
Show all NaN Threema features ▾
Threema VS Slack
Is Threema a good alternative to Slack?
- Threema is the most popular commercial alternative to Slack.
- Threema is Paid and Open SourceSlack is Freemium and Proprietary
- Threema is Privacy focusedSlack is not according to our users

Element X
It is the brand new, and fastest ever, Matrix client. It is for personal and community use, and will support enterprise functionality later this year.
74 Element X alternatives
+1
License model
- Free • Open Source
Application types
- Instant Messenger
- Video Calling App
Platforms
- Android
- iPhone
- Android Tablet
- iPad
Element X Features
1. VoiP Calls
2. Ad-free
3. Matrix Protocol
4. End-to-End Encryption
5. Privacy focused
6. Dark Mode
7. Decentralized
8. Lightweight
9. No Tracking
10. Voice Chat
Show all NaN Element X features ▾
Element X VS Slack
Is Element X a good alternative to Slack?

Conversations
Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].
151 Conversations alternatives
License model
- Free • Open Source
Application types
- Instant Messenger
- Group Chat App
Platforms
- Android
- Android Tablet
- F-Droid
+4
Top Conversations Features
1. Decentralized
2. End-to-End Encryption
3. Encrypted Chat
4. Image Sharing
5. OpenPGP
6. Lightweight
7. GPG Encryption
8. Dark Mode
9. Ad-free
10. Self Destructing Messages
11. Multiple Account support
12. Privacy focused
Show all NaN Conversations features ▾
Conversations VS Slack
Is Conversations a good alternative to Slack?

Nextcloud Talk
Nextcloud Talk is a fully self-hosted audio/video and chat communication service. It features web and mobile apps and is designed to offer the highest degree of security while being easy to use.
95 Nextcloud Talk alternatives
License model
- Free Personal • Open Source
Application types
- Video Calling App
- Group Chat App
Platforms
- Online
- Android
- iPhone
- iPad
- Self-Hosted
- Nextcloud
+5
Nextcloud Talk Features
1. Screen Sharing
2. End-to-End Encryption
3. Privacy focused
4. Ad-free
5. Real time collaboration
6. No registration required
7. No Tracking
Show all NaN Nextcloud Talk features ▾
Nextcloud Talk VS Slack
Is Nextcloud Talk a good alternative to Slack?

Mirotalk
Powered by WebRTC, Real-time video call, chat room and screen sharing entirely browser based.
53 Mirotalk alternatives
License model
- Free • Open Source
Application types
- Video Calling App
- Instant Messenger
Platforms
- Online
- Self-Hosted
Top Mirotalk Features
1. Screen Sharing
2. Desktop Sharing
3. Dark Mode
4. Privacy focused
5. End-to-End Encryption
6. Real time collaboration
7. VoiP Calls
8. No Tracking
9. Multiple Account support
10. Ad-free
11. No registration required
12. Voice Chat
Show all NaN Mirotalk features ▾
Mirotalk VS Slack
Is Mirotalk a good alternative to Slack?

Gitter
Gitter is a chat and collaboration tool for developers and users. It's a place for developers to talk.
47 Gitter alternatives
License model
- Free • Open Source
Application type
- Social Network
Platforms
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Android Tablet
- iPad
Gitter Features
Real time collaboration
Public communities discovery
Show all NaN Gitter features ▾
Gitter VS Slack
Is Gitter a good alternative to Slack?

TryQuiet
Quiet is an alternative to team chat apps like Slack, Discord, and Element that does not require trusting a central server or running one's own. In Quiet, all data syncs directly between a team's devices over Tor with no server required.
12 TryQuiet alternatives
License model
- Free • Open Source
Application types
- Group Chat App
- Encrypted Chat App
Platforms
- Windows
- Mac
- Linux
- Android
TryQuiet Features
1. Privacy focused
2. No registration required
3. Decentralized
4. Support for @mentions
5. End-to-End Encryption
6. IPFS Integration
7. Text chat
8. Cross-Platform
9. Multiple channels
10. Electron based
Show all NaN TryQuiet features ▾
TryQuiet VS Slack
Is TryQuiet a good alternative to Slack?