Mattermost vs Rocket.Chat

What Mattermost is

Mattermost is team messaging you can run on your own infrastructure, with a Slack-like interface and strong compliance features. Self-hosting is the entire point: message history stays on servers you control, which is what makes it viable for defence, healthcare and regulated finance where a hosted chat service is simply not permitted. The interface is close enough to Slack that migration costs little in training, and the source is open, so the deployment cannot be discontinued from outside.

What Rocket.Chat is

Rocket.Chat is open-source team messaging that can be self-hosted, including in restricted environments. It runs in environments where hosted chat is not allowed at all, including air-gapped networks, which is its clearest reason to exist. In exchange you operate it, and the polish gap against hosted rivals is visible.

What Mattermost is built to do

Self-hosted

Runs on your own servers or private cloud, with message data never leaving them.

Open source

The server is open source, so a deployment cannot be withdrawn by a vendor.

Compliance export

Legal hold, audit logging and export formats built for regulated environments.

Familiar interface

Channels, threads and integrations close enough to Slack to keep training short.

What Rocket.Chat is built to do

Self-hosted messaging

Runs the whole chat platform on your own infrastructure.

Federation and bridges

Connects to other chat networks and protocols.

Compliance controls

Applies retention, audit and data residency policies locally.

Choose Mattermost if

• Organisations that cannot put internal conversations on a third-party service.

Choose Rocket.Chat if

• Organisations that must keep messaging on their own infrastructure.

Mattermost: pros & cons

• Fully self-hostable, including in air-gapped environments
• Familiar channel-based interface
• Open source core
• Ecosystem of integrations is smaller than Slack's
• You carry the upgrade and backup burden
• Mobile apps lag behind commercial rivals

Rocket.Chat: pros & cons

• Fully self-hostable and open source
• Omnichannel customer messaging included
• Highly customisable
• Setup and maintenance are on you
• Interface less refined than commercial rivals
• Mobile apps have rough edges