Looking for an open-source alternative to Mattermost? Below are 3 community-built tools that offer similar functionality — all free, open source, and ready to use or self-host. Ranked by GitHub stars.
Rocket.Chat is a versatile open-source communication platform that prioritizes data protection and offers team collaboration, file sharing, and seamless integrations.
An open-source team chat that helps teams stay productive and focused.
Backend server powering the Signal Private Messenger, ensuring secure, end-to-end encrypted messaging and calling across Android, Desktop, and iOS.
The top picks from this list are Rocket.Chat, Zulip, Signal-Server — all maintained, free to use, and self-hostable.
Yes. Every tool listed here is open source and free to use. Many can be self-hosted on your own infrastructure, which means no subscription fees and full control over your data.
Most of the alternatives listed are self-hostable. Check each tool's page for hosting details, system requirements, and licensing terms.
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