head to head · open source
Rocket.Chat vs Mattermost
Rocket.Chat has 46,136 GitHub stars, 13,893 forks, 4,023 open issues and last shipped today. Mattermost has 39,096 stars, 9,005 forks, 1,012 open issues and last shipped today. Rocket.Chat leads on adoption by 18% (46,136 vs 39,096 stars). Rocket.Chat is written in TypeScript under a custom or non-standard licence; Mattermost is written in TypeScript under a custom or non-standard licence. Rocket.Chat has attracted 30% as many forks as stars, Mattermost 23%. Rocket.Chat was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (collaboration, hacktoberfest), 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
| Rocket.Chat | Mattermost | |
|---|---|---|
| GitHub stars | ★ 46K | ★ 39K |
| License | Custom / other | Custom / other |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-18 | 2026-09-18 |
| Forks | ⑂ 14K | ⑂ 9.0K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Rocket.Chat if
- You weight community size — 46K 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 Mattermost if
- You want the Mattermost feature set and don't need the biggest community
- You prefer the Custom / other license terms
- Your stack matches TypeScript
- You evaluated both and Mattermost fits your workflow better
About Rocket.Chat
Rocket.Chat is an open source, self hostable team communications platform written in TypeScript that gives organisations full ownership of their messaging, voice, and federation infrastructure instead of renting it from a closed SaaS vendor.
read the full Rocket.Chat overview →
About Mattermost
Mattermost is an open core, self hosted collaboration platform for teams that need secure chat, workflow automation, voice calling, screen sharing, and AI integration while keeping the deployment under their own control.
read the full Mattermost overview →
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Frequently asked questions
Is Rocket.Chat or Mattermost more popular?
Rocket.Chat has 46,136 GitHub stars and Mattermost has 39,096. Rocket.Chat has the larger community by that measure.
Are Rocket.Chat and Mattermost free?
Neither Rocket.Chat nor Mattermost declares a licence in this registry, so check each project's own repository before relying on either for a commercial use. Both are free to self-host.
What is the difference between Rocket.Chat and Mattermost?
Rocket.Chat is written in TypeScript and Mattermost in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Rocket.Chat or Mattermost?
Choose Rocket.Chat if you want the larger community (46,136 stars) or its Custom / other licence terms. Choose Mattermost if its feature set, stack or Custom / other licence fits better. Both are self-hostable.