Zulip

★ 25.6k · APACHE-2.0 · ACTIVE · ALT TO SLACK

Zulip is an open source alternative to Slack. Open-source team chat with topic-based threading for live and async work. Paid Zulip Cloud or self-host on Ubuntu, Debian, and Docker. Apache-2.0 licensed, 25.6k GitHub stars, hosted version available, self-host with Docker, no terminal required to start, and last released 2026-08-10.

Alternative toAll alternatives to Slack

How to start today

Should you switch?

Use it if

Teams that want topic-based threading to keep live and asynchronous conversations organized, with the option to self-host on Ubuntu or Debian.

Skip it if

You want a chat app with no server setup overhead and do not need threading, or expect a free hosted plan beyond sponsored open-source grants.

Watch out

Self-hosting targets Ubuntu or Debian Linux and requires server administration. The Docker image lives in a separate community repo (zulip/docker-zulip) from the main application.

Support the creator

Support this project directly once our USDC payment option launches.

Coming soon

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Community proof

"I've used Zulip. It's a cool idea, though it turned out to be still too beta to replace HipChat at my company. The key feature is having multiple threads of conversation in one room..."
rspeer · hacker_news · 2014-03-18

"We used Zulip for some time. Overall it's pretty good - the clients could really need a bit more love though. What I always found amazing was their support."
fallenhitokiri · hacker_news · 2014-03-18

Maintenance health

CadenceActive

Last release12.2 · 2026-08-10

Can you do it today?

Get started

1. Use the hosted versionZulip Cloud is paid; self-hosting is free under Apache 2.0. Sponsored free plans exist for worthy organizations.

Open hosted version ↗GitHub