# Open Source Alternative to Slack

Open source alternatives · Productivity

Slack costs US$8.75 per user monthly and deletes old messages on free plans. Mattermost is the open-source team chat you own.

**What the paid app costs:** US$8.75/user/mo

## Why switch?

Team chat holds your company's memory. On Slack's free tier that memory gets deleted after 90 days unless you pay per head. Self-hosted Mattermost or Zulip keeps every message forever, on hardware you control, at zero per-user cost.

## Compare the alternatives

AlternativeLicensePlatformsBest for[Mattermost](https://mattermost.com/)AGPL-3.0 / Apache-2.0Windows, macOS, Linux, iOS, Android, webThe open-source Slack for teams[Zulip](https://zulip.com/)Apache-2.0Windows, macOS, Linux, iOS, Android, webFor communities drowning in chat noise[Rocket.Chat](https://www.rocket.chat/)AGPL-3.0Windows, macOS, Linux, iOS, Android, webFor all-in-one team communication

### [Mattermost](https://mattermost.com/)

Free forever AGPL-3.0 / Apache-2.0 · Windows, macOS, Linux, iOS, Android, web

- Slack-style channels and threads
- Self-host for full privacy
- Calls and playbooks built in

**The open-source Slack for teams**

[Official site →](https://mattermost.com/)

### [Zulip](https://zulip.com/)

Free forever Apache-2.0 · Windows, macOS, Linux, iOS, Android, web

- Topic-based threading
- Built for large communities
- 100,000s of messages searchable

**For communities drowning in chat noise**

[Official site →](https://zulip.com/)

### [Rocket.Chat](https://www.rocket.chat/)

Free forever AGPL-3.0 · Windows, macOS, Linux, iOS, Android, web

- Channels, video, and omnichannel
- Federation support
- Self-hostable

**For all-in-one team communication**

[Official site →](https://www.rocket.chat/)

## Which one should you pick?

- **Mattermost:** The open-source Slack for teams
- **Zulip:** For communities drowning in chat noise
- **Rocket.Chat:** For all-in-one team communication

## Frequently asked questions

### Can I migrate my Slack history?

Yes, Mattermost and Zulip both import Slack export files, including channels and users.

### Is self-hosting chat hard?

Both ship Docker images; a small team runs fine on a $5/month VPS or a spare machine.

### What about video calls?

Mattermost has built-in calls; Zulip and Rocket.Chat integrate with Jitsi for free video meetings.

## More open source alternatives

- [Notion](/open-source-alternative-to-notion/)
- [Evernote](/open-source-alternative-to-evernote/)
- [Todoist](/open-source-alternative-to-todoist/)
- [Trello](/open-source-alternative-to-trello/)
- [Asana](/open-source-alternative-to-asana/)
- [Airtable](/open-source-alternative-to-airtable/)

[← All open source alternatives](/open-source-alternatives/)