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 many 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.
Slack alternatives are mainly Group Chat Apps but may also be Encrypted Chat Apps or Video Calling Apps. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of Slack.- Freemium • Proprietary
- Mac
- Windows
- Linux
- Android
- iPhone
- Chrome OS
- Android Tablet
- iPad
- Electron / Atom Shell
- Software as a Service (SaaS)
- Freemium • Open Source
- Mac
- Windows
- Linux
- Android
- iPhone
- Android Tablet
- iPad
- Self-Hosted
- JavaScript
- Go (Programming Language)
- Cloudron
Mattermost is a secure, open source platform for communication, collaboration, and workflow orchestration across tools and teams.
Mattermost vs Slack opinions
Its the same but you keep your server where you want so no one is playing with your data, and you can have an unlimited history depending on what you need for free so really way better !
Mattermost is quite versatile and has been used within several of my past employers.
liger1978Great interface, you control your data.
It's faster for one thing. It's far superior in terms of data ownership, and it's extremely scalable.
svelleHas more flexibility due to its extensive plugin system compared to other alternatives.
MudieLooks and works very much the same as Slack and complete control over your data housed separately from anyone else.
jaydelandOpen source with control over your data.
- Freemium • Open Source
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Android Tablet
- iPad
- Self-Hosted
- Matrix.org
- Cloudron
Element is a secure collaboration and messaging app based on the Matrix protocol. It’s decentralised to deliver digital sovereignty, and based on an open standard for easy connections and interoperability. It is end-to-end encrypted by default.
Element vs Slack opinions
xplosionmindIt is decentralized and it works with an open standard
User6044478decentralised, federated, end-to-end encrypted communication.
Privacy by design and based on matrix protocol!
Federated, decentralized, encrypted, open-source.
User6044478Open Source / Free Software,
brinerustlebecause its open source, decentralised, and end-to-end secure. Plus the folks at matrix.org are working to get us out of our communication silos by creating standards for communication interoperability!
Federated, free standard and free software
- Free Personal • Open Source
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Android Tablet
- BSD
- iPad
- Self-Hosted
Zulip is a group chat app in which messages are threaded by topic, helping you have long-running, organized conversations.
Zulip vs Slack opinions
the threading model is the best i've used for keeping up with active communities, and the open-source community is excellent.
It's a little different, for sure, but what it does, it does better than slack. Not a open source copy of slack like mattermost. If you want slack and nothing else, but in open source, stick to mattermost, if you want something that exceeds that, choose zulip.
paulocoghiMore than feature parity with Slack, it's better because of Streams and Topics. It offer the same free tier with 10.000 max messages and better paid plans to the hosted version, and also provide the open source self-hosted option to install it on your own server and also remove the max messages limits. 5 stars
The concept of topics to each message is a super useful feature :)
Zulip is open source and the methods of communications used is vastly different. It is specially useful in professional environments where different teams might want to participate in different conversations at the same time. Zulip solves this problem by including topics, where in each channel/stream, multiple topics can exist at once, at the same time.
superbicheOpen Source without limitations when on premises. Much better information categorisation with Streams & Topics. Vibrant community.
shantnukumarOne can easily switch in between conversation between different threads! Extremely helpful for any organisation.
- Freemium • Open Source
- Mac
- Windows
- Linux
- Android
- iPhone
- iPad
- Self-Hosted
- Cloudron
Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.
Rocket.Chat vs Slack opinions
Rocket.Chat comes very close to slack regarding it's core features and handling.
JohnFastmanDoes everything Slack does AND it's open source. However, it's also self-hosted. This means you have to put in the effort to set it up, but you control your own data, which is a huge advantage to your privacy - your chats and files don't sit on someone else's servers, ready for them or hackers to look at.
open source, locally hosted so you own your data.
- Free • Open Source
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Android Tablet
- iPad
- Self-Hosted
- WebRTC
- Python
- JavaScript
- Go (Programming Language)
- Cloudron
- Java
- Perl
Matrix defines a set of open APIs for decentralised communication, suitable for securely publishing, persisting and subscribing to data over a global open federation of servers with no single point of control.
Matrix.org vs Slack opinions
It can be easily bridged to many other chat systems, including Slack, which makes transitioning much easier. It's also open source and decentralized (self-hostable + communication with other servers).
Respects your Freedom. Increasingly popular
somegirlfromitMatrix is a protocol, not a client.
User6044478Open source, fecentralized, federation, chat-voice-video function.
Free open source instant messaging service with federation.
free, end-to-end encryption
nrg200Capable of everything Slack can do, but can be self-hosted - keeping a team's data in-house.
- Free Personal • Open Source
- Mac
- Windows
- Linux
- Online
- Android
- iPhone
- Android Tablet
- iPad
- Self-Hosted
- F-Droid
- Software as a Service (SaaS)
Wire is the most secure collaboration platform featuring messenger, voice, video, conference calls, file-sharing, and external collaboration –all protected by the most secure end-to-end-encryption.
- Paid • Open Source
- Online
- Android
- iPhone
- Android Tablet
- iPad
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.
- Free • Open Source
- Android
- Android Tablet
- F-Droid
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].
- Free • Open Source
- Online
- Windows
- Linux
- Android
Revolt is a brand new chat platform designed around you.
- Free Personal • Open Source
- Online
- Android
- iPhone
- iPad
- Self-Hosted
- Nextcloud
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.