Zulip
Depends
Confidence: Medium
Buy if your distributed team or community drowns in chat noise and will commit to the topic-threading model.
New check
Comparison
Zulip vs Rocket.Chat
Zulip and Rocket.Chat both land on Depends.
Rocket.Chat
Depends
Confidence: Medium
Buy if you're a government, defense, or regulated organization needing air-gapped, sovereign messaging with RBAC and E2EE.
| Compare | Zulip | Rocket.Chat |
|---|---|---|
| Verdict | Depends | Depends |
| Best for | Distributed teams drowning in chat noise | Government and defense agencies |
| Who it's not for | Teams wanting a drop-in Slack replacement with zero onboarding | Small teams wanting a simple Slack replacement |
| Privacy | Active security program (HackerOne disclosure, prompt releases), but multiple CVEs landed in 2025-26 including an authentication bypass.³ | Strong posture: end-to-end encryption, RBAC, air-gapped deployment, WCAG 2.1 AA conformance; one published CVE. |
| Support quality | No direct support-quality evidence found | No evidence in sources reviewed |
| Public sentiment | Reviewers consistently praise Zulip's organized, threaded conversations and pricing while admitting an adjustment period versus Slack.⁵ | Users average ~4.3/5, praising solid chat, channels, and document sharing while criticizing search and Slack-parity gaps. |
| Biggest gotcha | Self-hosters own updates: 2025-26 brought auth-bypass and info-disclosure CVEs³ | Most tier pricing is hidden behind 'contact sales' . no public numbers in sources14 |
Pick Zulip when
- Distributed teams drowning in chat noise
- Open-source communities
- Async-first remote orgs
- Buyers wanting self-hosting and data control
When Zulip is not a fit
- Teams wanting a drop-in Slack replacement with zero onboarding
- Small teams needing quick casual chat . threading is overkill
- Real-time social or gaming communities better served by Discord
- Self-hosters without time to patch security releases promptly
Pick Rocket.Chat when
- Government and defense agencies
- Critical infrastructure and healthcare
- Teams replacing Skype for Business Server
- Orgs needing on-prem or air-gapped deployment
When Rocket.Chat is not a fit
- Small teams wanting a simple Slack replacement
- Non-technical teams with no admin or ops capacity
- Anyone who needs polished search or huddles
- Companies without compliance or data-sovereignty requirements
Sources
- Zulip plans and pricingzulip.comofficial
- Zulip security pagezulip.comsecurity
- CVE-2025-31478 - NVDnvd.nist.govsecurity
- Zulip Server 12.2 security releaseblog.zulip.comsecurity
- Zulip Reviews on G2g2.comreview
- Zulip Reviews on Capterracapterra.comreview
- Zulip 11.0 discussion on r/selfhostedreddit.comreview
- New plans for self-hosted Zulip customers - Hacker Newsnews.ycombinator.comnews
- Zulip - Crunchbasecrunchbase.comnews
- Rust community case studyzulip.comofficial
- Zulip market share - 6sense6sense.comnews
- Zulip customer reviews - FeaturedCustomersfeaturedcustomers.comreview
- Rocket.Chat homepagerocket.chatofficial
- Rocket.Chat product security pagerocket.chatofficial
- RocketChat/Rocket.Chat on GitHubgithub.comofficial
- Introducing Secure CommsOS (blog)rocket.chatofficial