Slack dominates enterprise adoption with 750,000+ daily active users and superior integrations, while Zulip offers thread-based organization, lower costs ($0-$10/user/month vs $6.67-$12.50), and better message searchability for knowledge-heavy teams.
Slack vs Zulip — Side-by-side comparison on A Versus B
Cloud-based team messaging platform used by 750,000+ daily active users across enterprises.
Open-source team chat platform emphasizing organized conversations with topic-based threading and 50,000-100,000 active users.
Monthly Subscription Cost (per user). Daily Active Users Worldwide. Third-party App Integrations. Message Threading Model. Message Search Capability. Open Source Option. Enterprise SSO/SAML Support
Choose Slack if your organization prioritizes app ecosystem richness, mainstream vendor ecosystem, and can absorb higher costs for superior market integration and brand recognition. Choose Zulip if you value message organization, searchability, budget efficiency, want self-hosting control, or operate a knowledge-intensive team that benefits from topic-based threading and full message history access.
Slack: Up to 2,000 (with paid plan) | Zulip: N/A
Slack: Limited (third-party connectors) | Zulip: N/A
Slack: Slack AI (summarization, search, assisted writing) | Zulip: N/A
Slack: Excellent - optimized search indexing | Zulip: N/A
Slack: $3,600 (Pro plan at $15/user) | Zulip: $140 (Cloud Standard flat-rate)
Slack: 7 days | Zulip: 14 days + unlimited self-hosted
Slack: 10,000 most recent | Zulip: 100% unlimited
Slack: $8.25 (Pro plan, min 3 users) | Zulip: N/A
Slack: Unlimited (Slack Huddles for video limited to 50 participants) | Zulip: N/A
Slack: Huddles for brief video, limited to 50 participants; requires external tool for full conferencing | Zulip: N/A
Slack: Not native; requires integration with Otter.ai or similar third-party services | Zulip: N/A
Slack: 5 out of 5 (core feature with channels, threads, and history) | Zulip: N/A
Slack: 2 out of 5 (available via integration, not native) | Zulip: N/A
Slack: 30+ (CRM tools, meeting summaries, automation, SlackBot enhancements) | Zulip: N/A
Slack: Cloud-based SaaS only | Zulip: N/A
Slack: Compliant but data on Salesforce servers | Zulip: N/A
Slack: No increases for 33 months | Zulip: N/A
Slack: Unlimited group chats | Zulip: N/A
Slack: Workflow automation, search enhancement | Zulip: N/A
Slack: Optimized with threads and archives | Zulip: N/A
Slack: Slack AI (optional on paid plans) | Zulip: N/A
Slack: Limited (requires custom setup) | Zulip: N/A
Slack: Advanced with conditional logic | Zulip: N/A
Slack: Advanced AI assistant, smart summaries, automation | Zulip: N/A
Slack: $150 (billed monthly) | Zulip: N/A
Slack: 0 (not native feature) | Zulip: N/A
Slack: Unlimited (slide deck view only) | Zulip: N/A
Slack: DMs only, Enterprise+ plan | Zulip: N/A
Slack: Slack AI (search, summarization, drafting) | Zulip: N/A
Slack: $12.50 per user/month | Zulip: N/A
Slack: Advanced (Workflow Builder, automations) | Zulip: N/A
Slack: Unlimited external guests via workspace invite | Zulip: N/A
Slack: $8-12.50 (Pro/Business+) | Zulip: $0 self-hosted / $100-500 flat cloud
Slack: 10 years standard | Zulip: Unlimited (self-hosted)
Slack: Channel-based threads (contextual loss in active channels) | Zulip: Topic-based (complete conversation isolation within streams)
Slack: No (proprietary) | Zulip: Apache 2.0 open-source
Slack: Native iOS/Android with feature-parity | Zulip: Web-based with limited native apps
Slack: 50+ | Zulip: Custom via integrations (~15 standard)
Paid Workspaces/Users (Enterprise Adoption)
Slack: 750,000+ paid workspaces | Zulip: N/A
Slack: $150/month ($1,800/year) | Zulip: N/A
Slack: 90-day limited access | Zulip: N/A
Slack: 750,000+ active workspaces | Zulip: N/A
Slack: Yes (Business+ plan required) | Zulip: N/A
Slack: $12.50/user (Pro plan) | Zulip: N/A
Slack: 10,000 messages (free); unlimited (paid) | Zulip: N/A
Slack: No (requires integrations) | Zulip: N/A
Slack: 5GB (Free), varies by plan | Zulip: N/A
Slack: 1 GB shared workspace | Zulip: N/A
Annual Subscription Cost (Pro, 100 users)
Maximum video call participants (free tier)
Slack: 2,000+ apps (Slack App Directory) | Zulip: N/A
Slack: Cost-effective until ~12 users | Zulip: N/A
Slack: No: messaging-only, requires integrations | Zulip: N/A
Slack: 750+ million messages daily across 750k+ organizations | Zulip: N/A
Monthly Subscription Cost (Pro/Standard)
Slack: All messages indexed instantly | Zulip: N/A
Maximum Video Conference Participants (Free)
Slack: Limited (typically 3-4) | Zulip: N/A
Slack: 4.6/5 (12,400 reviews) | Zulip: N/A
Slack: Full-text indexed across all messages | Zulip: N/A
Slack: Partial (DMs only, beta feature) | Zulip: N/A
Cost Per User (Annual, Lowest Paid Tier)
Slack: Certified (SOC 2 Type II, GDPR) | Zulip: N/A
Monthly Cost Per User (Standard Tier, Annual Billing)
Slack: 0 GB (integrations only) | Zulip: N/A
Maximum Video Conference Participants (Standard Plan)
Slack: 10,000 (free tier); unlimited (paid) | Zulip: N/A
Slack: 10,000 (free), unlimited (paid) | Zulip: N/A
Slack: 1-4 hours (Enterprise Grid) | Zulip: N/A
Slack: Unlimited (90-day history) | Zulip: N/A
Slack: Full-featured messaging | Zulip: N/A
Slack: ~50 million (daily active) | Zulip: N/A
Paying Organizations/Enterprise Customers
Slack: 750 (in thousands = 750,000 paying orgs) | Zulip: N/A
Slack: SOC 2, ISO 27001, GDPR | Zulip: N/A
Slack: 21 million daily active | Zulip: N/A
Slack: Slack AI assistant included | Zulip: N/A
Slack: Limited on free plan (10,000 messages); full search on paid | Zulip: Full history search across all plans
Slack: Channel + Reply threads | Zulip: Channel + Topic threads (native)
Slack: 15 | Zulip: Requires third-party integration
Slack: Not available (cloud-only) | Zulip: Yes (open-source)
Slack vs Zulip — Structured Comparison Data
Machine-readable comparison dataset for Slack vs Zulip. Contains 201 attribute comparisons, 5 FAQ pairs.
Slack vs Zulip — Attribute Category Vocabulary
Taxonomy of attribute categories used to classify comparison data for Slack vs Zulip.
Which platform is cheaper for a 50-person team?
Zulip is significantly cheaper. For 50 users: Slack costs $167-$312/month (at $6.67-$12.50/user); Zulip's Pro plan costs $99/month flat rate or $0 with self-hosting. Annual savings with Zulip: $800-$2,556 per year for a 50-person team.
Can I switch from Slack to Zulip and keep my message history?
Yes, Zulip provides migration tools to import Slack workspaces, including channels, users, and message history. However, thread context may require manual reorganization due to differing threading models. Slack to Zulip migrations typically take 1-2 hours for teams under 100 users.
Why is Zulip's topic-based threading better for large teams?
Zulip's topics organize conversations hierarchically within channels (Channel → Topic → Messages), preventing reply thread fragmentation. In Slack, multiple reply threads in a channel create navigation clutter. Zulip teams report 40% faster message discovery due to this structured approach, especially beneficial for teams over 50 members.
Does Slack or Zulip have better integrations with Google Workspace?
Slack has more Google Workspace integrations (Google Drive, Sheets, Calendar, Docs). Zulip supports essential Google integrations but fewer specialized ones. For Google-heavy workflows, Slack is superior. However, both support OAuth authentication with Google accounts.
Yes, Zulip is open-source and can be self-hosted on your own infrastructure (Linux servers, Docker). This eliminates recurring SaaS costs beyond server maintenance, making it ideal for regulated industries (healthcare, finance) or large enterprises requiring on-premises deployment for compliance.
Consider: Monthly Subscription Cost (per user)
Monthly Subscription Cost (per user): Slack has $6.67 - $12.50, while Zulip has $0 - $10.00.
Daily Active Users Worldwide: Slack has 750,000+, while Zulip has 50,000-100,000.
Third-party App Integrations: Slack has 2,000+, while Zulip has 150+.
Message Threading Model: Slack has Reply threads (recent addition), while Zulip has Topic-based threading (native).
Message Search Capability: Slack has Basic search, limited free history, while Zulip has Full-text search across all history.
Open Source Option: Slack has None, while Zulip has Yes (self-hostable).
Enterprise SSO/SAML Support: Slack has Pro plan and above, while Zulip has Standard plan and above.