Open-source alternatives to Slack
9 open-source projects are offered as replacements for Slack. Rocket.Chat is the most starred. Running one yourself trades the subscription for your own hosting and upkeep, so the table below leads with what decides that trade: whether the project is alive, what its licence lets a business do, and whether there is a container command to start from.
Side by side
| Project | Stars | Activity | Licence | Self-host | Language |
|---|---|---|---|---|---|
 Rocket.Chat | 46,288 | Active | Not identified | ○ | TypeScript |
 Mattermost | 39,377 | Active | Not identified | ○ | TypeScript |
 Zulip | 26,069 | Active | Permissive | ○ | Python |
 Element | 13,593 | Active | Network copyleft | ○ | TypeScript |
 Cinny | 3,935 | Active | Network copyleft | ○ | TypeScript |
 Wire | 2,555 | Slowing | Copyleft | ○ | ○ |
 Revolt | 2,321 | Slowing | Not identified | ○ | ○ |
 Movim | 2,065 | Active | Network copyleft | ○ | PHP |
 Twake | 197 | Quiet | Not identified | ○ | ○ |
Each one, briefly
- Rocket.Chat46,288 stars · not identified · active
The Secure CommsOS™ for mission-critical operations
Also replaces Discord, Microsoft Teams
- Mattermost39,377 stars · not identified · active
Mattermost is an open source platform for secure collaboration across the entire software development lifecycle..
Also replaces Discord, Microsoft Teams
- Zulip26,069 stars · permissive · active
Zulip server and web application. Open-source team chat that helps teams stay productive and focused.
Also replaces Discord, Microsoft Teams
- Element13,593 stars · network copyleft · active
A glossy Matrix collaboration client for the web.
Also replaces Discord, Microsoft Teams
- Cinny3,935 stars · network copyleft · active
Yet another matrix client
Also replaces Discord, Microsoft Teams
- Wire2,555 stars · copyleft · slowing
Overview of the open source code for Wire
Also replaces Discord, Microsoft Teams
- Revolt2,321 stars · not identified · slowing
Repository for miscellaneous repository management and discussions: https://github.com/revoltchat/revolt/discussions
Also replaces Discord, Microsoft Teams
- Movim2,065 stars · network copyleft · active
Movim - Decentralized social platform
Also replaces Discord, Facebook, Twitter
- Twake197 stars · not identified · quiet
Twake Workplace : the open-source digital workplace
Also replaces Discord, Microsoft Teams
Where this comes from
Which projects are offered against Slack comes from opensourcealternative.to, re-read weekly. Every figure in the table is read from the project’s own repository. We have not run these projects, and we hold no price for Slack. Browse every open-source alternative.