Slack is a cloud-hosted SaaS platform with 750,000+ active workspaces and superior integrations, while Mattermost is a self-hosted open-source alternative costing 60-70% less with full data control. Slack dominates enterprise adoption; Mattermost suits organizations prioritizing privacy and cost savings.
Mattermost vs Slack — Side-by-side comparison on A Versus B
Choose Mattermost if your organization prioritizes data sovereignty, cost efficiency, and regulatory compliance—it's ideal for government, healthcare, and enterprises with strict security requirements. Choose Slack if you need best-in-class integrations, enterprise support, and seamless team collaboration at scale without infrastructure management overhead.
Open-source, self-hosted team collaboration platform designed for organizations requiring data control and customization.
Cloud-based SaaS team communication platform with 750,000+ active workspaces and 2,000+ native integrations.
Structured comparison data for Mattermost vs Slack with 185 attributes.
Annual TCO (1,000 users, 3-year average)
Paid Workspaces/Users (Enterprise Adoption)
Annual Subscription Cost (Pro, 100 users)
Maximum video call participants (free tier)
Monthly Subscription Cost (Pro/Standard)
Maximum Video Conference Participants (Free)
Cost Per User (Annual, Lowest Paid Tier)
Monthly Cost Per User (Standard Tier, Annual Billing)
Maximum Video Conference Participants (Standard Plan)
Mattermost vs Slack — Attribute Category Vocabulary
Taxonomy of attribute categories used to classify comparison data for Mattermost vs Slack.
Is Mattermost truly cheaper than Slack long-term?
Yes, significantly. Mattermost self-hosted costs $4-8 per user monthly, while Slack's Professional plan starts at $8.75/user and Pro at $12.50/user. For a 100-person team over 3 years, Mattermost saves $14,400-$25,200. However, factor in IT infrastructure costs (server, maintenance, backups), which can offset savings for small teams under 50 users.
Can I migrate from Slack to Mattermost without losing data?
Mattermost provides official import tools for Slack workspaces, including message history, users, channels, and files. Migration preserves most data, though some Slack-specific features (workflows, canvas) may require manual reconfiguration. Plan 1-2 weeks for a full enterprise migration with validation.
Why does Slack have 4x more integrations than Mattermost?
Slack's 2,000+ integrations reflect its 15-year market dominance and larger developer ecosystem. Slack has over 750,000 active workspaces incentivizing third-party developers. Mattermost's 500+ integrations cover 90% of enterprise use cases (Jira, GitHub, Salesforce, Microsoft Teams), though niche tools may require custom webhooks.
Which platform is more secure: Mattermost or Slack?
Both are enterprise-grade secure, but differently. Mattermost offers superior data sovereignty (air-gapped, on-premises deployment) ideal for HIPAA/FedRAMP/SOC2 compliance. Slack offers managed infrastructure with automatic updates and penetration testing but relies on cloud trust. For regulated industries (healthcare, government, finance), Mattermost's self-hosted model is preferred; for standard SaaS companies, Slack's managed security is sufficient.
How do Mattermost and Slack compare for team productivity features?
Slack leads with advanced features: AI-powered search, Canvas (collaborative documents), Workflow automation, and 2,000+ integrations enabling complex automation. Mattermost includes core features (channels, threads, mentions, file sharing, basic automation) but requires custom development for advanced workflows. Slack is more feature-rich out-of-the-box; Mattermost requires configuration but allows full customization via plugins.