Best Self-Hosted and Secure Team Chat

Team messaging for organisations that need control over where their data lives: self-hosting, end-to-end encryption, data residency and admin audit trails. Mattermost and Rocket.Chat are the most complete self-hosted Slack alternatives, Element runs on the open Matrix protocol with end-to-end encryption and federation, and Zulip's topic threads suit engineering and research teams. AWS Wickr targets regulated and government use, Threema and Signal are privacy-first messengers for smaller groups, and Revolt is an open-source option for communities. Read our guide to self-hosted team chat for regulated teams on the blog.