Element vs Rocket.Chat vs Mattermost: The 3-Way Chat Comparison

Three open source Slack alternatives, three different philosophies. Element is decentralized. Rocket.Chat is omnichannel. Mattermost is developer-focused. Here's the definitive breakdown.

Quick Verdict

Need	Winner
Best Slack replacement	Mattermost
Best for customer support	Rocket.Chat
Best for privacy/security	Element (Matrix)
Best DevOps integration	Mattermost
Best omnichannel	Rocket.Chat
Best for federation	Element (Matrix)
Easiest to deploy	Mattermost
Most features	Rocket.Chat

Full Comparison

Feature	Element	Rocket.Chat	Mattermost
Architecture	Decentralized	Centralized	Centralized
E2E encryption	✅ Default	✅	Enterprise
Federation	✅ Native	✅ (Matrix bridge)	Enterprise
Video calls	✅ Built-in	✅ Built-in	Plugin
Livechat widget	❌	✅	❌
Omnichannel	Bridges	✅ Native	❌
DevOps integrations	Basic	✅	✅ Best
Playbooks/incidents	❌	❌	✅
Boards/PM	❌	❌	✅ (Focalboard)
Bots	✅	✅	✅
Mobile apps	✅	✅	✅
UX quality	Good	Good	Best
Database	PostgreSQL	MongoDB	PostgreSQL
Language	Python/Go	Node.js	Go
RAM (100 users)	2-4 GB	2-4 GB	1-2 GB
Performance	Good	Fair	Best

The Decision Tree

Do you need E2E encryption by default?
  YES → Element (Matrix)
  NO ↓

Do you need customer-facing livechat or omnichannel?
  YES → Rocket.Chat
  NO ↓

Do you need DevOps integrations (Jira, GitHub, PagerDuty)?
  YES → Mattermost
  NO ↓

Do you need federation with other organizations?
  YES → Element (Matrix)
  NO → Mattermost (simplest, fastest)

The Bottom Line

• Mattermost is the best team chat for most organizations — focused, fast, great DX
• Rocket.Chat is the best communication platform — customer support + team chat
• Element is the best for security and interoperability — encryption and federation

Most teams should start with Mattermost unless they have specific needs for omnichannel (Rocket.Chat) or encryption/federation (Element).

---

Compare all three on OSSAlt — detailed feature breakdowns, performance benchmarks, and community health.