5 Best Open-Source Mattermost Alternatives (2026)

Mattermost: open-source, self-hostable team messaging platform. Of the 10 alternatives we track, 5 match the "Open source" filter. Zulip is the closest match, sharing 80% of Mattermost's tracked attributes. Every option links to its own alternatives, so you can keep exploring.

Last reviewed October 19, 2026 · 5 alternatives