Rocket.Chat

Open SourceOtherSelf-hostable

Highly customizable open-source communications platform with team chat, voice, video and omnichannel customer messaging — a Slack alternative you can extend freely.

Open source alternative to

Slack

Visit Rocket.Chat View source

About Rocket.Chat

Rocket.Chat covers more ground than most Slack alternatives: internal team chat, voice and video calls, and omnichannel customer messaging across WhatsApp, SMS and live chat all live in one self-hostable platform.

It's MIT licensed, has a large app marketplace for extending functionality, and has been battle-tested for over a decade — making it a flexible pick for teams that want both internal collaboration and customer-facing messaging in one system.

Key features

Team chat + omnichannel — Internal messaging and customer-facing channels like WhatsApp and live chat in one platform.
Voice & video calls — Built-in calling alongside chat, without needing a separate conferencing tool.
App marketplace — Extend functionality with a large marketplace of community and official apps.
Self-hostable — Deploy fully on your own infrastructure, keeping every conversation under your control.

The honest read

What we like

Covers internal chat and customer-facing omnichannel in one platform
MIT licensed
Huge plugin and app marketplace
Long, proven track record
Highly customizable

Worth knowing

MongoDB-based self-hosting can be resource-hungry at scale
UI customization has a learning curve
Some omnichannel features push toward paid tiers
Upgrades between major versions need care

FAQ

Is Rocket.Chat free to use?

Yes — Rocket.Chat's core is free and open source under MIT, with paid tiers for advanced omnichannel and enterprise features.

Does Rocket.Chat support customer messaging?

Yes — it supports omnichannel customer messaging across WhatsApp, SMS and live chat, in addition to internal team chat.

Can I self-host Rocket.Chat?

Yes — Rocket.Chat has an official Docker setup and a long history of self-hosted deployments.

How is Rocket.Chat different from Mattermost?

Rocket.Chat adds omnichannel customer messaging and voice/video on top of team chat, while Mattermost focuses more narrowly on secure internal messaging for technical teams.