What is the difference between Mattermost and Rocket.Chat?

Mattermost is best for Teams that need self-hosted, privacy-first messaging, while Rocket.Chat is best for Teams that want self-hosted chat with customer-facing features. Mattermost starts at Free (self-hosted) and Rocket.Chat starts at Free (self-hosted).

Is Mattermost or Rocket.Chat cheaper?

Mattermost starts at Free (self-hosted) and is free. Rocket.Chat starts at Free (self-hosted) and is free.

Is there a free alternative to Rocket.Chat?

Both Mattermost and Rocket.Chat offer free tiers.

Mattermost vs Rocket.Chat

Mattermost is open-source, self-hosted team messaging platform for organizations that need data sovereignty, while Rocket.Chat is open-source communication platform with team chat, video, and omnichannel customer engagement. Mattermost is built for teams that need self-hosted, privacy-first messaging, whereas Rocket.Chat targets teams that want self-hosted chat with customer-facing features.

At a glance

	Mattermost	Rocket.Chat
Best for	Teams that need self-hosted, privacy-first messaging	Teams that want self-hosted chat with customer-facing features
Starting price	Free (self-hosted)	Free (self-hosted)
Free tier	✓	✓
Open source	✓	✓
Free tier available	✓	✓
Open source	✓	✓
Bots	—	✓
Channels	✓	—
Compliance	✓	—
Federation	—	✓
Integrations	✓	—
Omnichannel	—	✓
Playbooks	✓	—
Self-Hosted	✓	✓
Video Calls	—	✓

Mattermost

Strengths

Self-hosted — full control over your data
Open source with active community
Slack-compatible interface, easy migration
Strong compliance and security features

Weaknesses

Requires server management if self-hosting
Smaller integration ecosystem than Slack
Cloud-hosted version is more expensive than Slack
Mobile apps lag behind Slack and Teams in polish

Try Mattermost → Full review

Rocket.Chat

Strengths

Self-hosted with full data ownership
Combines internal chat and customer-facing messaging
Active open-source community
Federation support for cross-organization chat

Weaknesses

UI feels dated compared to Slack
Self-hosting requires significant DevOps effort
Fewer integrations than mainstream alternatives
Can be resource-intensive to run

Try Rocket.Chat → Full review

The bottom line

Pricing: Both Mattermost and Rocket.Chat are free, so this decision comes down to features and philosophy rather than budget.

Feature gaps: Mattermost offers Channels, Compliance and Integrations that Rocket.Chat lacks. Rocket.Chat brings Bots, Federation and Omnichannel that Mattermost does not have. Both share Self-Hosted.

Team fit: Both tools target mid-size teams teams, so the decision hinges on features and workflow fit rather than scale.

Open source: Both Mattermost and Rocket.Chat are open source, so self-hosting and code audits are on the table with either choice.

Where each tool shines: Mattermost's biggest strengths are: self-hosted — full control over your data. open source with active community. Rocket.Chat's biggest strengths are: self-hosted with full data ownership. combines internal chat and customer-facing messaging.

Watch out for: With Mattermost, users commonly note that requires server management if self-hosting. With Rocket.Chat, the main complaint is that ui feels dated compared to slack.

Choose Mattermost if...

Your profile matches its sweet spot: teams that need self-hosted, privacy-first messaging
You specifically need Channels and Compliance
You care about open source with active community

Choose Rocket.Chat if...

Your profile matches its sweet spot: teams that want self-hosted chat with customer-facing features
You specifically need Bots and Federation
You care about combines internal chat and customer-facing messaging