SlackAbout 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.
What makes it different
Internal messaging and customer-facing channels like WhatsApp and live chat in one platform.
Built-in calling alongside chat, without needing a separate conferencing tool.
Extend functionality with a large marketplace of community and official apps.
Deploy fully on your own infrastructure, keeping every conversation under your control.
TypeScript
React
MongoDB
DockerThe honest read
- Covers internal chat and customer-facing omnichannel in one platform
- MIT licensed
- Huge plugin and app marketplace
- Long, proven track record
- Highly customizable
- 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
Quick answers
Yes — Rocket.Chat's core is free and open source under MIT, with paid tiers for advanced omnichannel and enterprise features.
Yes — it supports omnichannel customer messaging across WhatsApp, SMS and live chat, in addition to internal team chat.
Yes — Rocket.Chat has an official Docker setup and a long history of self-hosted deployments.
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.
More open-source picks
Secure team messaging and collaboration for technical teams.
Threaded team chat that keeps async conversations organized.
All-in-one project management, virtual office and team chat.
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