Mattermost vs Rocket.Chat: Self-Hosted Team Chat Compared

Mattermost and Rocket.Chat are the two heavyweights of open source team chat. Both replace Slack. Both are self-hosted. But they take different approaches — Mattermost is focused and developer-oriented; Rocket.Chat is feature-packed and omnichannel. Here's how to decide.

Quick Verdict

Choose Mattermost for a focused, developer-friendly Slack replacement with excellent DevOps integrations. Choose Rocket.Chat for an omnichannel communication platform with video, livechat, and WhatsApp integration.

The Comparison

Feature	Mattermost	Rocket.Chat
Core focus	Team messaging	Omnichannel communication
GitHub stars	30K+	41K+
Stack	Go, React	Node.js (Meteor), React
License	MIT (TE: proprietary)	MIT
Channels	✅	✅
Threads	✅	✅
Direct messages	✅	✅
File sharing	✅	✅
Search	✅ (Elasticsearch optional)	✅
Video calls	Plugin (Jitsi, Zoom)	✅ Built-in
Screen sharing	Via plugin	✅ Built-in
Livechat/widget	❌	✅
Omnichannel	❌	✅ (WhatsApp, SMS, etc.)
Bots	✅	✅
Webhooks	✅	✅
Slash commands	✅	✅
App marketplace	✅	✅
LDAP/SAML	✅	✅
E2E encryption	Enterprise	✅
Federation	Enterprise	✅ (Matrix bridge)
Desktop app	✅	✅
Mobile app	✅	✅
DevOps integrations	✅ (best)	✅
RAM usage	500MB-1GB	1-2GB
Performance	Faster (Go)	Heavier (Node.js)

Deep Dive: Mattermost

Strengths:

• Performance: Go backend is faster and uses less memory than Rocket.Chat's Node.js
• DevOps focus: Best-in-class integrations with Jira, GitHub, GitLab, Jenkins, PagerDuty
• Playbooks: Built-in incident management and runbooks
• Boards: Focalboard integrated for project management alongside chat
• Plugin ecosystem: Well-documented plugin API
• Enterprise backing: Strong commercial company, predictable roadmap

Weaknesses:

• No built-in video calling (requires Jitsi/Zoom plugin)
• No livechat widget for websites
• Some features gated to Enterprise Edition
• No omnichannel (WhatsApp, SMS integration)

Deep Dive: Rocket.Chat

Strengths:

• Omnichannel: WhatsApp, Facebook Messenger, SMS, email, livechat in one platform
• Built-in video: Video calling and screen sharing without plugins
• Livechat widget: Embeddable customer support chat
• Federation: Matrix protocol bridge for cross-server communication
• End-to-end encryption: Available in community edition
• More features: Out of the box, Rocket.Chat does more

Weaknesses:

• Heavier resource usage (Meteor/Node.js stack)
• Can feel slower with large teams
• UI is busier and less polished than Mattermost
• Some features deprecated or changed frequently
• Smaller enterprise market compared to Mattermost

Deployment Comparison

Mattermost:

docker run -d --name mattermost \
  -p 8065:8065 \
  -v mattermost-data:/mattermost/data \
  -v mattermost-config:/mattermost/config \
  mattermost/mattermost-team-edition

Rocket.Chat:

docker compose up -d  # Requires MongoDB

	Mattermost	Rocket.Chat
Database	PostgreSQL/MySQL	MongoDB
Min RAM	1 GB	2 GB
Min CPU	1 core	2 cores
Disk	10 GB	10 GB

When to Choose Mattermost

• Developer and DevOps teams
• Organizations wanting Slack-like focus
• Performance-sensitive deployments
• Teams needing Jira/GitHub/GitLab integration
• Enterprises wanting predictable, well-backed OSS

When to Choose Rocket.Chat

• Customer support teams (livechat widget)
• Organizations needing omnichannel (WhatsApp, SMS)
• Teams wanting built-in video calling
• Deployments requiring Matrix federation
• Organizations needing E2E encryption in community edition

The Bottom Line

Mattermost is the better Slack replacement — focused, fast, and developer-friendly. Rocket.Chat is the better communication platform — omnichannel, livechat, video, and federation in one. If you just need team chat, go Mattermost. If you need customer communication too, go Rocket.Chat.

Production Deployment and Scaling

Both tools require more planning than a single Docker run command once you take them to production. The scaling characteristics are quite different, which matters if you are planning for a team of 100 or 500 users.

Mattermost scales horizontally well. Its Go backend is stateless, and Mattermost officially supports a clustered deployment where multiple application nodes sit behind a load balancer and share a PostgreSQL database. The key constraint is the PostgreSQL instance — under heavy read load, you will want read replicas. File storage can point to S3-compatible object storage (MinIO for self-hosted) so files are accessible from all nodes without a shared filesystem. Push notification delivery goes through Mattermost's notification proxy, which you can self-host as well to keep all data on your infrastructure.

Rocket.Chat's Meteor foundation creates a different scaling story. Meteor was designed for real-time applications and uses MongoDB's oplog for real-time event propagation. Scaling Rocket.Chat typically means running multiple application instances behind a load balancer with sticky sessions, all connected to a MongoDB replica set. The Meteor DDP protocol uses WebSockets, and session affinity — ensuring a user's WebSocket connections stay on the same application node — is important for correct behavior. MongoDB should be deployed as a replica set from the start, even for small teams, because adding replication later is painful.

Storage requirements grow quickly for both platforms. Every file upload, image paste, and video message consumes disk space. For production deployments with many users, configure external S3-compatible storage from day one. Both tools support MinIO, Backblaze B2, Wasabi, and AWS S3. Local filesystem storage works for small teams but creates migration headaches when you eventually need to scale.

For teams considering Mattermost specifically, our guide to migrating from Slack to Mattermost covers the full migration process, including exporting Slack history, mapping channels, and onboarding your team on the new platform.

Security, Encryption, and Compliance

Security models differ between these two platforms in ways that matter for regulated industries and high-security environments.

Mattermost in the Team Edition (MIT-licensed, free) does not include end-to-end encryption for messages. Channel and direct message content is encrypted in transit via TLS, but the server can read all messages in the clear — a standard model for centralized communication platforms. Mattermost Enterprise adds compliance export features, audit logging to external systems, and data retention policies. If you need E2E encryption in Mattermost, there are community plugins, but they are not first-party supported.

Rocket.Chat includes end-to-end encryption in the community edition. When E2E encryption is enabled for a room, messages are encrypted client-side before leaving the browser or app, and the server stores only ciphertext. This is a meaningful privacy guarantee for sensitive discussions. The trade-off is that server-side search stops working for E2E-encrypted rooms, and message export for compliance purposes captures ciphertext rather than plaintext.

Both platforms support LDAP and Active Directory integration for authentication, which is essential for enterprise deployments where you want centralized identity management. Both also support SAML, which enables SSO through identity providers like Okta, Azure AD, and Keycloak. For teams running a self-hosted identity stack, the Authentik vs Keycloak comparison covers which identity provider pairs best with self-hosted applications.

Guest access — allowing external users to join specific channels without being full members — is available in both platforms. Mattermost's guest account feature is available in Team Edition and is straightforward to configure. Rocket.Chat supports federated guest access through the Matrix bridge, which is more powerful but also more complex to set up.

Integrations and the Broader Self-Hosted Stack

Neither platform exists in isolation. Teams choosing self-hosted team chat are usually building or extending a broader self-hosted infrastructure stack. The integration story matters as much as the chat features themselves.

Mattermost has the best native integrations for developer tooling. GitLab has a first-party Mattermost integration that posts pipeline status, merge request notifications, and deployment events. GitHub's bot ecosystem works via incoming webhooks. PagerDuty and Opsgenie both have official integrations for incident alerting. For teams running on-call rotations and incident response workflows, Mattermost Playbooks — a built-in incident management feature with checklists and retrospectives — makes Mattermost a stronger operational platform than Rocket.Chat.

Rocket.Chat's integration strength is in customer-facing communication. The omnichannel inbox aggregates messages from WhatsApp Business, Facebook Messenger, Twitter/X DMs, SMS, and website livechat into a unified agent interface. This is genuinely different functionality from what Mattermost offers — it is closer to Intercom or Zendesk for customer support than to Slack for team communication. Organizations that need both internal team chat and customer support in one platform will find Rocket.Chat's omnichannel capabilities compelling.

For teams evaluating the broader landscape of self-hosted team communication, including options beyond Mattermost and Rocket.Chat, our best open source team communication tools guide covers the full field including Element (Matrix), Zulip, and others. Element in particular is worth evaluating for teams with strong federation requirements, since its Matrix foundation enables interoperability between separately administered servers without the complexity of Rocket.Chat's Matrix bridge.

Migration From Slack: Practical Considerations

Teams moving to self-hosted chat from Slack face two parallel challenges: technical migration and cultural adoption. The technical side is the easier half.

Mattermost offers the most direct Slack import path. Their official Slack import tool processes the Slack export ZIP file and recreates channels, messages, files, and user mappings. The main limitation is that Slack exports for paid teams include all message history, but Slack exports for free teams are limited to 90 days. Emoji reactions, threaded replies, and direct message history all import reasonably well. What does not import cleanly: Slack app integrations, custom emoji that are not in the Mattermost emoji set, and workspace-specific configuration. Plan for a few hours of cleanup and reconfiguration after the import.

The cultural challenge is more variable. Mattermost's interface is familiar enough to Slack users that most people adapt within a week. The keyboard shortcuts differ (compose window behavior, channel navigation), and features like Workflow Builder do not have equivalents in the free Mattermost tier. Engineering teams adapt fastest because they are accustomed to tooling changes. Customer success and sales teams, who rely heavily on Slack's app integrations, need more transition support.

Our guide to migrating from Slack to Mattermost covers both sides of the migration — the technical import process and the change management approach — with a rollout plan that has worked for teams from 20 to 500 people.

Long-Term Cost of Ownership

Slack charges $7.25–12.50/user/month depending on plan. For a 50-person team on Slack Pro, that is $4,350–7,500/year. Mattermost Team Edition (free, MIT-licensed) on a Hetzner CX21 at $7/month costs $84/year for the same team. The infrastructure cost scales negligibly with team size — a single server handles hundreds of concurrent users for most team chat workloads.

Rocket.Chat's community edition is similarly priced for self-hosting — the server costs are the only expense. Both platforms have paid tiers for enterprise features like advanced compliance, dedicated support, and certain integrations, but the community editions handle the vast majority of real-world team chat needs without limitation.

The hidden cost comparison is maintenance time. A Go-based Mattermost instance is stable and requires minimal maintenance — security updates every few months, database backups, and occasional version upgrades. Rocket.Chat's Node.js and MongoDB stack historically requires more operational attention, particularly around MongoDB version upgrades and memory tuning as the database grows. For teams without dedicated DevOps capacity, Mattermost's lower maintenance burden is a genuine operational advantage over a multi-year time horizon. The Element vs Mattermost comparison is also worth reading for teams weighing federation capability against operational simplicity.

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