Slack is a cloud-based SaaS platform owned by Salesforce with extensive integrations and AI features, while Mattermost is a self-hosted open-source alternative offering greater control and lower costs for privacy-conscious organizations. Slack excels in ease-of-use and ecosystem, while Mattermost provides deployment flexibility and data sovereignty.
Mattermost vs Slack — Side-by-side comparison on A Versus B
Slack is the superior choice for most organizations seeking an easy-to-use, feature-rich communication platform with extensive integrations and AI capabilities. Mattermost is ideal for enterprises prioritizing data sovereignty, cost control, and regulatory compliance where self-hosting is acceptable. The choice depends on whether you prioritize convenience and ecosystem (Slack) or control and cost (Mattermost).
Open-source, self-hosted team collaboration platform with enterprise security controls
Cloud-based team messaging platform with deep enterprise integrations and 21 million daily active users.
Structured comparison data for Mattermost vs Slack with 167 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)
Mattermost vs Slack — Attribute Category Vocabulary
Taxonomy of attribute categories used to classify comparison data for Mattermost vs Slack.
How do these platforms handle team growth and scalability?
Slack automatically scales with cloud infrastructure, supporting unlimited growth without infrastructure concerns. Mattermost requires proper server sizing and administration but offers unlimited users with single deployment. For organizations expecting rapid growth, Slack's automated scaling is advantageous, while Mattermost's unlimited-user model benefits predictable enterprise expansion.
Which platform is more cost-effective for large enterprises?
Mattermost is significantly more cost-effective for large organizations. While Slack's Pro tier costs $7.25/user/month, Mattermost's Professional plan is $10/user/month but includes unlimited team members and channels. For organizations with 500+ users, self-hosting Mattermost can reduce costs by 40-60% compared to Slack's per-seat pricing model.
Yes, migration is possible but requires technical effort. Mattermost provides import tools for Slack data including messages, channels, and user information. However, integrations must be reconfigured separately. Many organizations use migration tools from third-party providers to streamline the process. Full migration typically takes 2-4 weeks depending on workspace size.
Is Slack secure for regulated industries?
Slack meets compliance standards including SOC 2, HIPAA, and GDPR, making it suitable for regulated industries. However, data remains on Salesforce's infrastructure. For organizations with strict data residency requirements (requiring data stored in-country), Mattermost's self-hosting option provides greater control and compliance flexibility.
What are the main productivity differences between these platforms?
Slack excels in productivity through its vast integration ecosystem (2000+ apps), advanced AI assistant for search and automation, and polished user experience that requires minimal training. Mattermost provides solid collaboration features but with fewer native integrations. For teams heavily reliant on third-party tools, Slack typically offers superior workflow automation and efficiency.