# 2 Best Open-Source Alternatives to Zulip in 2026

By Noah — last updated & pricing verified September 15, 2026.

> 2 of the 5 Zulip alternatives we list qualify for this filter. The [full list](https://findalternative.to/zulip) is the canonical page.

| Alternative | Best for | Price | Details |
| --- | --- | --- | --- |
| Mattermost | regulated, government, or defense organizations that need self-hosted, air-gapped, or sovereign-cloud team chat with compliance controls a SaaS-only tool like Slack can't provide | Free | https://findalternative.to/mattermost/about |
| Rocket.Chat | regulated and security-conscious organizations (government, defense, healthcare, financial services) that need a self-hostable or air-gapped team chat platform, plus teams wanting a free, open-source Slack alternative | Free | https://findalternative.to/rocket-chat/about |

All 5 alternatives to Zulip: https://findalternative.to/zulip

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Markdown mirror of https://findalternative.to/zulip/open-source — findalternative.to, honestly ranked software alternatives. AI info: https://findalternative.to/ai