Mattermost is a free, open-source Microsoft Teams alternative for team channels, direct messages and calls. Teams is paid per user each month; self-hosted Mattermost has no per-user price and keeps chats on your server.
| App | Good for | Code | Import from Microsoft Teams | Ease of use |
|---|---|---|---|---|
 Mattermost | Small teams that want Slack-style chat with unlimited history on their own server | Code Open source | Import from Microsoft Teams No | Easy |
Microsoft Teams is Microsoft's chat and meetings app, part of Microsoft 365. It combines chat channels, video meetings, calling and file sharing through SharePoint and OneDrive.
Teams look for an alternative when they want chat without the rest of the Microsoft 365 package, when they find Teams heavy and slow for everyday messaging, or when they want conversations kept on a server they control rather than in Microsoft's cloud. A self-hosted chat app such as Mattermost gives you Slack-style channels and threads on your own server, with no price per user in its free edition.
Open-source team chat like Slack, with your full history kept.
A focused chat app rather than an office suite. It covers channels, threads, direct messages, file sharing and one-to-one calls, and works with whatever email and document tools you already use. Group video meetings are not part of the free edition.
There is no import from Microsoft Teams, so teams usually start fresh: recreate the channels you use, invite everyone, and keep Teams available for a few weeks for old conversations. Files shared in Teams are stored in SharePoint and OneDrive, so move the ones you still need to a file-sharing app such as Nextcloud. For video meetings, keep a separate meeting tool or use Mattermost's paid editions.
Mattermost is the free, open-source alternative to Microsoft Teams for team chat and calls in the catalogue today. A focused chat app rather than an office suite. It covers channels, threads, direct messages, file sharing and one-to-one calls, and works with whatever email and document tools you already use. Group video meetings are not part of the free edition.
Not fully on the free edition, which has one-to-one calls only. Many teams pair Mattermost with a separate video meeting tool.
No. Mattermost works on its own, in a browser or its desktop and phone apps, with any email and document tools.
Yes, the app is free. To run them you need Cloudgate and a server. Use hosted Cloudgate, which can also provide the server, or install Cloudgate on a server of your own for free. Cloudgate's plans and prices are at cloudgate.octabyte.io/pricing. One server can run several apps.
No. Cloudgate installs the app on your server and gives it a secure web address. You use it in your browser.
