Zulip

Open source alternative to Slack, Microsoft Teams and Google Chat

26.1K stars
Apache-2.0
Active this week
Last commit 2 days ago

Last verified Oct 20, 2026

Collaborate in threaded team chat with powerful search and self-hosting on your own infrastructure.

Visit website GitHub26.1K 1-click deploy on Hostinger

Read the full breakdownWho it is for, how it works, trade-offs and the FAQ

who it's for

Who Zulip is for#

Remote engineering teams coordinating decisions

Zulip keeps architecture, incident, release, and support conversations separated by topic while still living in shared team streams.

Skip if:

Your team mainly uses chat for quick social coordination and does not want to enforce topic naming.

Open source communities with public support channels

Maintainers can point contributors to focused topics and keep answers discoverable across time zones.

Skip if:

Your community depends heavily on voice rooms, live events, or broad consumer familiarity with Discord.

the problem

The problem it solves#

Fast chat tools work well for live coordination, but they turn messy when a team discusses several decisions in the same channel. Important answers get buried between status updates, newcomers have to read long scrollback, and remote teams repeat the same questions because no one can find the thread that settled the issue.

The pain gets sharper for open source communities, research groups, and engineering teams with members across time zones. They need asynchronous discussion that stays organized by topic, not just a searchable stream of every message ever sent.

how Zulip solves it

How it solves it#

Topic-based conversations

Every stream message belongs to a topic, so multiple discussions can happen in the same team space without mixing decisions, questions, and status updates.

Self-hosted server option

Zulip publishes its server code under Apache-2.0, giving teams a path to run chat on their own infrastructure instead of keeping all history in a proprietary SaaS account.

Developer-focused integrations

The project documents integrations, bots, webhooks, and an API so engineering teams can connect deployments, CI alerts, issue trackers, and custom workflows to chat.

Cross-platform clients

Official web, desktop, and mobile clients let teams keep the same threaded conversation model across laptops and phones.

strengths · trade-offs

Strengths and trade-offs#

Strengths

Better async structure than channel-only chatTopic threads make Zulip easier to scan after time away than Slack-style channels where unrelated conversations interleave chronologically.
Apache-2.0 licensingThe permissive license supports internal modification and commercial use without the network-copyleft obligations that some team chat platforms carry.

Trade-offs

-Different mental modelTeams used to casual channel chat need to adopt topic hygiene. Without that habit, Zulip loses much of its advantage over Slack or Discord.
-Self-hosting is an operations commitmentRunning the server means maintaining databases, email delivery, backups, upgrades, and push notification configuration instead of delegating that work to Zulip Cloud.

versus alternatives

Zulip vs alternatives#

Zulip vs Slack

Zulip and Slack both handle team chat, integrations, mentions, and searchable history. The main difference is conversation structure: Zulip requires topics inside streams, while Slack centers channels and optional threads.

Criteria	Zulip	Slack
License	Apache-2.0 server	Proprietary
Self-hosting	Yes	No
Conversation model	Topic-first streams	Channel-first messages
Best fit	Async teams and communities	Teams that want the largest SaaS chat ecosystem

Zulip is the better choice when async discussion quality matters more than SaaS familiarity. Slack is still the better fit when your organization depends on Slack-native apps, enterprise administration, or users who will resist a topic-first workflow.

tech stack · detected from GitHub

What it's built on#

Languages: JavaScriptPythonTypeScript
Frameworks: React Native
Tooling: Webpack

frequently asked

FAQ#

Is Zulip open source?

Yes. Zulip Server is open source under the Apache-2.0 license, with official clients and integrations available through the Zulip project.

Can Zulip replace Slack?

Zulip can replace Slack for teams that value threaded async discussion, searchable history, and self-hosting. Slack remains stronger for teams that rely on a large app marketplace and familiar channel-first workflows.

Can I self-host Zulip?

Yes. Zulip provides a self-hosted server path, but production operation requires normal chat infrastructure work such as email, backups, upgrades, and push notification setup.

Looking for more

Other ways to replace Slack, Microsoft Teams and Google Chat#

Buzz

Featuredfor Slack

Self-hosted team chat where people and AI agents work together

36,174Visit

Mattermost

#1 in the Slack guide

Closest drop-in Slack replacement for self-hosted teams

39,388

Rocket.Chat

#2 in the Slack guide

Teams needing internal chat and customer omnichannel in one tool

46,298

Macro Chat

#4 in the Slack guide

Channels wired into the docs, tasks, and email around them

4,782

All 17 Slack alternatives 8 open source Slack alternatives, ranked

by category

Open source tools in these categories#

126

Hostinger

Run Zulip on your own server

Hostinger sets Zulip up as a one-click app on a VPS.

Deploy on Hostinger

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Who Zulip is for#

Remote engineering teams coordinating decisions

Zulip keeps architecture, incident, release, and support conversations separated by topic while still living in shared team streams.

Skip if:

Your team mainly uses chat for quick social coordination and does not want to enforce topic naming.

Open source communities with public support channels

Maintainers can point contributors to focused topics and keep answers discoverable across time zones.

Skip if:

Your community depends heavily on voice rooms, live events, or broad consumer familiarity with Discord.

The problem it solves#

How it solves it#

Topic-based conversations

Every stream message belongs to a topic, so multiple discussions can happen in the same team space without mixing decisions, questions, and status updates.

Self-hosted server option

Zulip publishes its server code under Apache-2.0, giving teams a path to run chat on their own infrastructure instead of keeping all history in a proprietary SaaS account.

Developer-focused integrations

The project documents integrations, bots, webhooks, and an API so engineering teams can connect deployments, CI alerts, issue trackers, and custom workflows to chat.

Cross-platform clients

Official web, desktop, and mobile clients let teams keep the same threaded conversation model across laptops and phones.

Strengths and trade-offs#

Strengths

Better async structure than channel-only chatTopic threads make Zulip easier to scan after time away than Slack-style channels where unrelated conversations interleave chronologically.
Apache-2.0 licensingThe permissive license supports internal modification and commercial use without the network-copyleft obligations that some team chat platforms carry.

Trade-offs

-Different mental modelTeams used to casual channel chat need to adopt topic hygiene. Without that habit, Zulip loses much of its advantage over Slack or Discord.
-Self-hosting is an operations commitmentRunning the server means maintaining databases, email delivery, backups, upgrades, and push notification configuration instead of delegating that work to Zulip Cloud.

Zulip vs alternatives#

Zulip vs Slack

Criteria	Zulip	Slack
License	Apache-2.0 server	Proprietary
Self-hosting	Yes	No
Conversation model	Topic-first streams	Channel-first messages
Best fit	Async teams and communities	Teams that want the largest SaaS chat ecosystem

FAQ#

Is Zulip open source?

Yes. Zulip Server is open source under the Apache-2.0 license, with official clients and integrations available through the Zulip project.

Can Zulip replace Slack?

Can I self-host Zulip?

Yes. Zulip provides a self-hosted server path, but production operation requires normal chat infrastructure work such as email, backups, upgrades, and push notification setup.

Other ways to replace Slack, Microsoft Teams and Google Chat#

Buzz

Featuredfor Slack

Self-hosted team chat where people and AI agents work together

36,174Visit

Mattermost

#1 in the Slack guide

Closest drop-in Slack replacement for self-hosted teams

39,388

Rocket.Chat

#2 in the Slack guide

Teams needing internal chat and customer omnichannel in one tool

46,298

Macro Chat

#4 in the Slack guide

Channels wired into the docs, tasks, and email around them

4,782

All 17 Slack alternatives 8 open source Slack alternatives, ranked

Who Zulip is for#

Remote engineering teams coordinating decisions

Skip if:

Open source communities with public support channels

Skip if:

The problem it solves#

How it solves it#

Topic-based conversations

Self-hosted server option

Developer-focused integrations

Cross-platform clients

Strengths and trade-offs#

Strengths

Trade-offs

Zulip vs alternatives#

Zulip vs Slack

What it's built on#

FAQ#

Other ways to replace Slack, Microsoft Teams and Google Chat#

Open source tools in these categories#

Communication & Collaboration

Business & Productivity

IT Management

Find open source alternatives to paid software

Who Zulip is for#

Remote engineering teams coordinating decisions

Skip if:

Open source communities with public support channels

Skip if:

The problem it solves#

How it solves it#

Topic-based conversations

Self-hosted server option

Developer-focused integrations

Cross-platform clients

Strengths and trade-offs#

Strengths

Trade-offs

Zulip vs alternatives#

Zulip vs Slack

What it's built on#

FAQ#

Other ways to replace Slack, Microsoft Teams and Google Chat#

Open source tools in these categories#

Communication & Collaboration

Business & Productivity

IT Management

Find open source alternatives to paid software