Mattermost Open Source: Full Control Without the Slack Bill
Deploy a self-hosted team chat platform with 39K GitHub stars. Unlimited message history, unlimited users, no per-user fees. Opsily handles backups, updates, and EU data residency. Start your free trial today.
Saved per year switching from Slack
A 10-person team on Slack Pro (€120/month) switches to managed Mattermost with unlimited message history and no vendor lock-in.
Why Teams Switch From Slack to Mattermost
Slack pricing current as of Sept 2026. Mattermost Team Edition is free; managed hosting cost shown for Opsily plans.
What Mattermost Open Source Offers
Mattermost is a self-hosted, open-source team communication platform built for organizations that need full control over their data. It is MIT-licensed, meaning you can deploy it anywhere, audit the code, and modify it for your team's needs.
Core Features
Messaging: Channels (public and private), direct messages, threaded conversations, and priority-flagged messages for every workflow.
File sharing: Drag-and-drop uploads, automatic thumbnails, search across all attachments, no deletion limits.
Calls: Integrated voice and video calling with screen sharing. Supports up to 50 concurrent users per server.
Integrations: 700+ integrations with Jira, Jenkins, GitHub, Zoom, PagerDuty, and hundreds more. Build custom integrations via webhooks, slash commands, and REST API.
Search: Full-text search across messages, channels, and files. Unlimited message history in Team Edition—no paywall.
Customization: Adjust branding, themes, and workflows to match your organization's needs.
Mattermost Team Edition (free) scales to 250 active users with all core features. Enterprise Edition (paid) removes the user ceiling and adds advanced capabilities like Playbooks (incident response automation), Boards (Kanban management), and AI-powered summarization.
Deployed by Uber (70K concurrent users), Samsung, GitLab, the U.S. Department of Defense, Wargaming, and thousands of open-source communities.
Why Opsily for Mattermost Open Source
You chose Mattermost for its transparency and control. Opsily removes the operational burden without sacrificing either.
EU Data Residency
Deploy in your choice of EU regions: Germany, Finland, Netherlands, UK, or Sweden. Your application data stays where you specify. ISO 27001 certified and GDPR compliant. Perfect for regulated industries, government, and teams subject to data protection rules.
Zero Vendor Lock-In
Mattermost is MIT-licensed open-source. Export your full database, configuration, and files anytime—no restrictions. Migrate to another provider, host it yourself, or switch to third-party hosting without losing a message. Your data belongs to you.
Transparent Pricing
No per-user fees. No seat limits. No surprise bills when your team grows. Pricing is based on hosting resources, not headcount. Automated backups, security updates, SSL certificates, and 99.9% uptime are included in every plan.
Built for teams who need reliability
Deploy Mattermost in Minutes
Opsily handles the infrastructure, updates, and backups. You just invite your team and start collaborating.
Create your Opsily account and pick the hosting tier that matches your team size and usage.
Select Mattermost from the app catalog and click Deploy. Your instance is live in minutes—fully configured and secure.
Create user accounts, set up teams and channels, and invite colleagues. Bulk import from Slack if migrating.
Create your Opsily account and pick the hosting tier that matches your team size and usage.
Select Mattermost from the app catalog and click Deploy. Your instance is live in minutes—fully configured and secure.
Create user accounts, set up teams and channels, and invite colleagues. Bulk import from Slack if migrating.
Sign up and choose your plan
Create your Opsily account and pick the hosting tier that matches your team size and usage.
Deploy Mattermost
Select Mattermost from the app catalog and click Deploy. Your instance is live in minutes—fully configured and secure.
Invite your team
Create user accounts, set up teams and channels, and invite colleagues. Bulk import from Slack if migrating.
Start collaborating
Post messages, share files, create threads, integrate your tools, and enjoy unlimited message history forever.
Transparent Pricing for Every Team
All plans include daily encrypted backups, automated updates, SSL certificates, GDPR-compliant EU hosting, and 99.9% uptime SLA. Choose based on your team size and resource needs.
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Enterprise-Grade Security
Mattermost is trusted by Uber, Samsung, GitLab, the U.S. Department of Defense, and thousands of open-source communities. Opsily adds infrastructure-level protection.
GDPR Compliant
Your data is processed and stored in the EU. We follow GDPR requirements for data handling, retention, and deletion.
ISO 27001 Certified
Third-party audited. Our infrastructure and processes meet international information security standards.
Encrypted Backups
Daily automated backups with AES-256 encryption. Restore anytime, anywhere.
EU Data Centers
Deploy in Germany, Finland, Netherlands, UK, Sweden, or other EU regions. Application data stays where you choose.
Open Source
MIT-licensed source code. Audit the platform yourself. No closed-door features or hidden logic.
Questions About Mattermost Open Source
Everything you need to know about deploying self-hosted Mattermost on Opsily.
Mattermost's Team Edition is fully open-source under the MIT license, meaning the code is public and free to audit, modify, and deploy. The Enterprise Edition adds proprietary features like Playbooks and AI integration, but Team Edition contains everything Slack offers: channels, DMs, file sharing, integrations, video calls, and threaded conversations. You can inspect every line of code or deploy without any licensing restrictions. The source is on GitHub with 39K stars and 23,229 commits, backed by active development and a thriving community.
Stop Paying Per User. Start Your Free Trial Today.
Deploy managed Mattermost in minutes. No credit card required. Test it with your team and see why Uber, Samsung, and GitLab trust Mattermost.