Host Mattermost without installing anything
Team messaging in channels, with threads and mobile apps — and a history nobody cuts off after ninety days.
Starting at €15.99/month
Introduction
Mattermost installed, updated and backed up by us, on a machine in France. You install nothing and configure no server: the application is online a few minutes after you order, under your own name.
The plan that suits it is App Performance at €15.99/month incl. VAT — 8 GB of memory. Mattermost holds a permanent connection open for every connected client — laptop, phone, browser tab — and each one takes its share. Alongside that, PostgreSQL keeps in memory the search index that sweeps several years of messages and files. 2 GB is enough to start the application; the 8 GB are what a team of twenty needs never to notice the server.
Moving from Slack starts with your workspace export, a JSON archive that the official tool converts into Mattermost's import format before loading it: public channels, messages, threads and members. After that, the desktop and mobile apps are the official ones from the App Store and Google Play; you enter your server address on first launch, and nothing else changes for your team.
What Mattermost does
Channels, threads, and the whole history
Public and private channels, direct messages, threads attached to a message. Nothing is erased after three months: search reaches back to the first line written on the server.
The official apps, pointed at your server
Desktop on Windows, macOS and Linux, mobile on iOS and Android. Notifications can be set to carry an identifier only, the app fetching the content straight from your own server.
Bots, webhooks and slash commands
One incoming webhook is enough to drop monitoring alerts, tickets or a Forgejo repository's activity into the right channel. Slash commands fire your scripts without leaving the conversation.
Calls and screen sharing are included
The calls module is part of the installation: an audio conversation starts from a channel, with screen sharing, without opening a third-party video service.
Who uses it, and what for
An agency of twelve leaving Slack
The reason is nearly always the same: the history. Three years of technical decisions become searchable again, and the bill no longer follows the number of people logged in.
A technical team that wants alerts in the right place
Uptime Kuma, Healthchecks and the code repository write into a dedicated channel through webhooks. The person on call reads one interface instead of three mailboxes.
An organisation whose exchanges cannot leave
A practice, a firm, a department handling named files: the conversation stays on a machine in France, under your own domain name.
A charity and its working groups
One channel per committee, accounts for the volunteers, and exchanges that do not dissolve in an email thread with thirty recipients.
A company working with contractors
Private channels opened for the length of a project and closed on delivery, without giving access to the rest of the house.
Hosted in France
In our own infrastructure in Nouvelle-Aquitaine, which we operate ourselves. A company's internal conversations are rarely trivial: they stay in the country.
Frequently asked questions
Slack provides a workspace export as a JSON archive. Mattermost's official tool converts it into the platform's import format and loads it: public channels, messages, threads and members. Direct messages and attachments depend on the export level your Slack plan grants — that is the point to check before scheduling the switch.
The free edition covers channels, threads, files, search, apps, webhooks, bots and calls. The enterprise edition adds SAML authentication, synchronisation with an LDAP or Active Directory, automatic retention policies, compliance exports and fine-grained role permissions. For a team with no directory to plug in, the difference does not show.
Notifications on a phone necessarily go through Apple or Google, that is how the platforms work. Mattermost can however send an identifier only, without the text of the message: once woken, the app fetches the content directly from your server. That is the setting to remember if your exchanges are sensitive.
App Performance, at €15.99/month incl. VAT. It provides 8 GB of memory where the application asks for 2 GB at minimum: the headroom serves the system, not the decor. You can change plan later without reinstalling.
Yes, they are part of the service. A self-hosted application left un-updated is a security risk, not a saving.