head to head · open source
Mattermost vs Zulip
Mattermost has 39,510 GitHub stars, 9,087 forks, 1,012 open issues and last shipped yesterday. Zulip has 26,158 stars, 10,521 forks, 2,008 open issues and last shipped yesterday. Mattermost leads on adoption by 51% (39,510 vs 26,158 stars). Mattermost is written in TypeScript under a custom or non-standard licence; Zulip is written in Python under Apache-2.0. Mattermost has attracted 23% as many forks as stars, Zulip 40%. Mattermost was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (collaboration, react-native), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Mattermost | Zulip | |
|---|---|---|
| GitHub stars | ★ 40K | ★ 26K |
| License | Custom / other | Apache-2.0 |
| Written in | TypeScript | Python |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 9.1K | ⑂ 11K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Mattermost if
- You weight community size — 40K stars and counting
- You want the Custom / other license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick Zulip if
- You want the Zulip feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Python
- You evaluated both and Zulip fits your workflow better
About Mattermost
Mattermost is an open core, self hosted collaboration platform that offers chat, workflow automation, voice calling, screen sharing, and AI integration. This repo is the primary source for core development on the Mattermost platform; it's written in Go and React, runs as a single Linux binary, and relies on PostgreSQL. A new compiled version is released under an MIT license every month on the 16th. Deploy Mattermost on premises, or try it for free in the cloud. Learn more about the following use cases with Mattermost: DevSecOps Incident Resolution IT Service Desk Other useful resources: Download and Install…
read the full Mattermost overview →
About Zulip
Zulip overview Zulip is an open source organized team chat app with unique [topic based threading][why zulip] that combines the best of email and chat to make remote work productive and delightful. Fortune 500 companies, [leading open source projects][rust case study], and thousands of other organizations use Zulip every day. Zulip is the only [modern team chat app][features] that is designed for both live and asynchronous conversations. Zulip is built by a distributed community of developers from all around the world, with 99+ people who have each contributed 100+ commits. With over 1,500 contributors merging…
read the full Zulip overview →
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Frequently asked questions
Is Mattermost or Zulip more popular?
Mattermost has 39,510 GitHub stars and Zulip has 26,158. Mattermost has the larger community by that measure.
Are Mattermost and Zulip free?
Both are open source. Mattermost has no licence declared in this registry, and Zulip is licensed under Apache-2.0. Both are free to self-host.
What is the difference between Mattermost and Zulip?
Mattermost is written in TypeScript and Zulip in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Mattermost or Zulip?
Choose Mattermost if you want the larger community (39,510 stars) or its Custom / other licence terms. Choose Zulip if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.