Home · Compare · Slack / Discord alternatives
Mattermost vs Rocket.Chat
Short answer: Mattermost and Rocket.Chat are both self-hostable alternatives to Slack / Discord. Pick Rocket.Chat if community size is your main criterion – it has 1.2× the stars. Pick Rocket.Chat if license terms matter to you (for example, you plan to modify it or offer it to others): MIT (+ separate enterprise/EE license for some dirs) is permissive, while Mattermost's AGPL-3.0 (source; compiled builds MIT, admin tools/config Apache-2.0) is network copyleft. Pick Mattermost if its feature set fits your use case better – stars, license and activity don't measure features, so try both on a test server.
Rocket.Chat has 1.2× the GitHub stars of Mattermost (46.3k vs 39.4k). Stars measure popularity and community size, not quality. Both are actively developed: Mattermost's last push was on 2026-10-19 (on the day of our check); Rocket.Chat's last push was on 2026-10-19 (on the day of our check).
Mattermost vs Rocket.Chat at a glance
| Mattermost | Rocket.Chat | |
|---|---|---|
| GitHub stars | ★ 39.4k | ★ 46.3k |
| Forks | 9.1k | 14.0k |
| License | AGPL-3.0 (source; compiled builds MIT, admin tools/config Apache-2.0) (file) | MIT (+ separate enterprise/EE license for some dirs) (file) |
| License type | network copyleft | permissive |
| Last push | 2026-10-19 on the day of our check | 2026-10-19 on the day of our check |
| Latest GitHub release | v12.0.0 2026-10-14 | 8.9.0 2026-10-05 |
| Main language | TypeScript | TypeScript |
| Archived | no | no |
| Repository | mattermost/mattermost | RocketChat/Rocket.Chat |
Data: GitHub REST API, checked 2026-10-19. Licenses verified manually against each project's license file. Self-hosting difficulty (Slack: medium, Discord: hard) is our rating per use case and applies to both.
In their own words
Mattermost (GitHub description): Mattermost is an open source platform for secure collaboration across the entire software development lifecycle..
Rocket.Chat (GitHub description): The Secure CommsOS™ for mission-critical operations
Which should you pick?
- Pick Rocket.Chat if community size is your main criterion – it has 1.2× the stars.
- Pick Rocket.Chat if license terms matter to you (for example, you plan to modify it or offer it to others): MIT (+ separate enterprise/EE license for some dirs) is permissive, while Mattermost's AGPL-3.0 (source; compiled builds MIT, admin tools/config Apache-2.0) is network copyleft.
- Pick Mattermost if its feature set fits your use case better – stars, license and activity don't measure features, so try both on a test server.
Mattermost is AGPL-3.0 (source; compiled builds MIT, admin tools/config Apache-2.0), Rocket.Chat is MIT (+ separate enterprise/EE license for some dirs). Both are written mainly in TypeScript. License note for Mattermost: Source code: AGPL-3.0 or a commercial license from Mattermost, Inc. Compiled versions produced by Mattermost, Inc.: MIT. Admin tools and configuration files (server/templates, server/i18n, server/public, webapp/): Apache-2.0. License note for Rocket.Chat: MIT for everything outside ee/ and apps/meteor/ee/; those have their own license.
FAQ
Which is more popular, Mattermost or Rocket.Chat?
Rocket.Chat has 1.2× the GitHub stars of Mattermost (46.3k vs 39.4k). Stars measure popularity and community size, not quality.
Are Mattermost and Rocket.Chat actively maintained?
Both are actively developed: Mattermost's last push was on 2026-10-19 (on the day of our check); Rocket.Chat's last push was on 2026-10-19 (on the day of our check). Latest GitHub releases: Mattermost v12.0.0 (2026-10-14), Rocket.Chat 8.9.0 (2026-10-05).
What licenses do Mattermost and Rocket.Chat use?
Mattermost: AGPL-3.0 (source; compiled builds MIT, admin tools/config Apache-2.0) – network copyleft (AGPL: if you run a modified version as a service for others, you must publish your changes). Rocket.Chat: MIT (+ separate enterprise/EE license for some dirs) – permissive (MIT/Apache/BSD-style: few obligations). Rocket.Chat keeps some code under a separate license (open-core).
Is Mattermost or Rocket.Chat easier to self-host?
We rate self-hosting difficulty per use case, not per project: medium for Slack alternatives, hard for Discord alternatives. Both need a server you maintain; check each project's install docs for the exact services (database, workers) it needs.
Should I pick Mattermost or Rocket.Chat?
Pick Rocket.Chat if community size is your main criterion – it has 1.2× the stars. Pick Rocket.Chat if license terms matter to you (for example, you plan to modify it or offer it to others): MIT (+ separate enterprise/EE license for some dirs) is permissive, while Mattermost's AGPL-3.0 (source; compiled builds MIT, admin tools/config Apache-2.0) is network copyleft. Pick Mattermost if its feature set fits your use case better – stars, license and activity don't measure features, so try both on a test server.
All alternatives
Both are listed in the directory, next to other options and a build-it-yourself-with-AI prompt:
More comparisons
Recommended hosting
Disclosure: some links are affiliate links. If you sign up through them we may earn a commission at no extra cost to you. It never affects which tools we list. Details
One self-hosted swap per week
A new SaaS teardown and its open-source replacement, every week. No spam.
We only use your email to send the SelfHostThis newsletter (stored with our email provider Resend, EU). Every email has a one-click unsubscribe link, and you can ask us to delete your data anytime. We use double opt-in. Datenschutz · Privacy policy