AntimatterCompare
Antimatter vs Mattermost
Antimatter is a fork of Mattermost: it keeps its server, its APIs and its integrations. What differs is the licensing, the interface and the apps.
Why teams choose Antimatter
- Every feature is free software under the AGPL: SSO, LDAP sync, compliance export, data retention and the rest come with every server.
- A new interface, with voice channels, roles and badges, onboarding and moderation tools.
- Built-in notes, whiteboards, todo lists, calendar and mail, and AI transcription without extra services.
- It keeps Mattermost's APIs, so integrations written for Mattermost keep working.
When Mattermost may suit you better
- You want commercial support, with SLAs, from the company that makes the software.
- You need certified builds, such as FIPS 140-3 or STIG-hardened images.
- You need features Antimatter hasn't got yet, such as high-availability clustering tested at large scale or legal hold.
Feature by feature
| Feature | Antimatter | Mattermost |
|---|---|---|
| Hosting and licensing | ||
| Self-hosted on your own servers | ✓ Yes | ✓ Yes |
| Open-source server | ✓ YesAGPL v3 | ◐ Partlyenterprise features are proprietary |
| Every feature without a paid plan | ✓ Yes | ✕ No |
| Runs offline, without internet access | ✓ Yes | ✓ Yes |
| Messaging | ||
| Channels, direct messages and threads | ✓ Yes | ✓ Yes |
| Unlimited message history | ✓ Yes | ✓ Yes |
| Scheduled messages and reminders | ✓ Yes | ✓ Yes |
| Message priority and acknowledgements | ✓ Yes | ◐ Partlyacknowledgements on paid plans |
| Self-destructing (burn-on-read) messages | ✓ Yes | ◐ PartlyEnterprise Advanced |
| Automatic translation of channels | ✓ Yesself-hosted models | ◐ PartlyEnterprise Advanced |
| Calls | ||
| Voice and video calls with screen sharing | ✓ Yes | ✓ Yes |
| Always-open voice channels | ✓ Yes | ✕ No |
| Live captions and call transcripts | ✓ Yesyour own speech-to-text | ◐ PartlyEnterprise |
| Apps and AI | ||
| Collaborative notes and documents | ✓ Yes | ✕ No |
| Whiteboards | ✓ Yes | ✕ No |
| Kanban boards | ✓ Yes | ◐ Partlycommunity plugin |
| Incident and process checklists | ✓ Yes | ✓ YesPlaybooks |
| Polls | ✓ Yes | ◐ Partlyplugin |
| AI assistants with the models you choose, self-hosted included | ✓ Yes | ◐ Partlypaid plans |
| Security and administration | ||
| Single sign-on (SAML, OpenID Connect) | ✓ Yes | ◐ Partlypaid plans |
| LDAP and Active Directory sync | ✓ Yes | ◐ Partlypaid plans |
| Data retention and compliance export | ✓ Yes | ◐ PartlyEnterprise |
| Federation with other servers | ✓ Yesshared channels | ◐ PartlyEnterprise |
| End-to-end encryption of messages | ✕ No | ✕ No |
"Partly" means the feature needs a paid plan, an add-on or a plugin, or exists in a limited form; the note says which. Based on each product's public documentation as of October 2026: plans and features change, so check the vendor's own site before deciding. Spotted a mistake? Tell us.