Slack vs Mattermost
Pick Slack for a hosted chat tool with a large app marketplace; pick Mattermost if you need to host chat yourself and keep control of the data.
Pick Slack if…
You want a hosted, widely used chat tool with many integrations, and 90 days of searchable history is fine on the free plan or you will pay per user.
Pick Mattermost if…
You need self-hosted or air-gapped chat, or want a free open source edition you run on your own server.
Price
- Freemium
- Freemium
- Open source
Starting price
Free plan
Open source
Works on
| Feature | Workplace messaging with channels, huddles, workflows, search and AI features for teams. | Self-hostable team messaging with channels, playbooks, calls and integrations for secure teams. |
|---|---|---|
| Price |
|
|
| Starting price | $7.25 USD per user / month, when paying annually (Pro); $8.75 per user / month when paying monthly | — |
| Free plan | Yes | Yes |
| Open source | No | Yes |
| Works on | Windows, macOS, Linux, iOS, Android | Web, Windows, macOS, Linux, iOS, Android, API |
| Try Slack (opens the Slack website in a new tab) | Try Mattermost (opens the Mattermost website in a new tab) |
Slack's Free plan is $0 and saves and searches messages for 90 days. Pro is $7.25 USD per user per month paying annually ($8.75 monthly), Business+ is $15 annually ($18 monthly), and Enterprise+ is $45 per user per month paying annually through sales.
Mattermost does not publish paid prices. Professional, Enterprise and Enterprise Advanced are sold through sales as prepaid annual seat subscriptions. Free options exist: a Team Edition under MIT for fewer than 250 activated users, and an Entry edition limited to 10,000 visible channel messages and other caps, with community support only.
Both have apps on desktop and mobile. Slack lists desktop apps for Mac, Windows and Linux and mobile apps for iOS and Android, with 2,600+ marketplace apps. Mattermost lists Windows, macOS, Linux, iOS, Android and web, plus a REST API, webhooks, slash commands and plugins.
The core difference is who runs it. Slack is a hosted service. Mattermost can run self-hosted, in a private cloud or air-gapped, and its source is available under AGPL v3.0 with MIT-licensed compiled builds, though you maintain the server yourself.
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Last updated 16 October 2026. How we make money