The right Mattermost alternative turns on one question: must your chat run on servers you control? If not, a hosted chat app or a big collaboration suite is simpler to live with. If it must, your shortlist shrinks to the two tools here that state self-hosting or on-premises deployment. The rest of this page sorts all nine by what you're buying.
Start with the hosted apps. Unless a client contract, a security policy or a regulator has told you in writing that messages must stay on your own infrastructure, running chat yourself mostly adds chores: updates, backups, the odd outage at a bad moment.
Advice first: hosted unless someone insists
If your team mainly wants channels, threads and calls, choose between the light hosted apps and whichever big suite your company already logs into every morning. Only open the self-hosted shortlist when you can point to the document that demands it, and when you've got a named person who'll look after the server.
Whatever group you land in, run a week of your own conversations through two candidates. Real questions, real files, real calls. By Friday you'll know whether threads help or get in the way, whether notifications drive people mad and whether search finds last Tuesday's decision.
Why Mattermost now sells to national security teams
Mattermost's own homepage leads with sovereign operations and air-gapped deployment for national security, critical infrastructure and regulated teams. That's a far heavier brief than everyday team chat, so a smaller team may find the fit has changed even if the product still works. If you picked it years ago for open-source chat, the question now is whether you still need that level of control at all.
Suites, light chat apps and self-hosted tools
The big suites. Slack bills itself as a chat-based work platform where teams and AI agents work together. Microsoft Teams, by Microsoft's account, covers chat, meetings and calling. Webex is Cisco's platform, and the vendor groups collaboration with customer experience and devices. Lark calls itself a productivity superapp. All four do a lot, so expect more settings to learn.
The lighter hosted apps. Pumble, according to its site, covers channels, document sharing and video calls. Flock adds project management features to its channels, the vendor says, and Ryver's site puts a task manager and voice and video calls alongside group chat. If your team is small and mostly wants quick questions out of email, start in this group.
The self-hosted pair. Only two of the nine say on their own sites that you can run them yourself. Zulip describes its software as fully open source and self-hostable. Troop Messenger says it's offered both as SaaS and on-premises. If self-hosting really is a must, that's your shortlist.
If you'd like to look beyond chat, my roundups of collaboration tools for your business and cloud tools for remote teams cover the bigger picture.
Nine Mattermost replacements, alphabetically
Beyond the alphabet they're in no particular order, and each line describes the tool the way its maker does.
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Flock
Best for: Small teams who want, in the vendor's words, channels that help streamline decision making and problem solving.
Lark
Best for: Companies wanting a free starting point; the vendor says chat, docs, meetings, workflow automations and AI come free in one place.
Microsoft Teams
Best for: Organisations already on Microsoft's apps; the vendor says tools and files stay in one place designed to help you connect and stay organised.
Pumble
Best for: Growing teams who don't want to hit limits, since the vendor says its free-forever plan has no cap on users or message history.
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Ryver
Best for: Anyone tired of juggling several apps and email; the vendor's pitch is many ways to talk in one app.
Slack
Best for: Teams who like the vendor's idea that Slackbot multiplies what a connected team can do.
Troop Messenger
Best for: Businesses wanting one-to-one chat, group chat, bulk messages and secure meetings in a single app, per the vendor.
Webex
Best for: Cisco customers drawn to the vendor's pitch of agentic AI and people working together on a single platform.
Zulip
Best for: Distributed teams across time zones; the project describes itself as built for asynchronous conversations and publishes guidance for switching over.
Who each one suits, at a glance
| Tool | Kind of tool | Good for |
|---|---|---|
| Flock | Team messaging with project tools | Channels with light project features |
| Lark | Chat, docs and meetings superapp | One app for chat, docs and automations |
| Microsoft Teams | Chat, meetings and calling suite | Chat and meetings beside your files |
| Pumble | Team messaging with a free plan | Channels, file sharing and video calls |
| Ryver | Chat plus task manager | Chat, tasks and calls in one app |
| Slack | Team chat and AI work platform | Chat where people and AI agents work |
| Troop Messenger | Secure messaging, SaaS or on-premises | Chat you can run on-premises, per the vendor |
| Webex | Cisco collaboration platform | Collaboration alongside Cisco devices |
| Zulip | Threaded open-source team chat | Threaded chat for remote, async teams |
A five-step move off Mattermost
- Decide which channels and conversations you must keep, and archive the rest.
- Check what the new tool says it can import, and export what you need before you switch.
- Set up the core channels and integrations before inviting anyone.
- Move one team first and fix whatever annoys them.
- Pick a date when the old workspace goes read-only, and stick to it.
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Frequently asked questions
Why does Mattermost's homepage talk about air-gapped setups?
It now pitches itself at national security, critical infrastructure and regulated teams that need private cloud, self-hosted or air-gapped deployment. Everyday team chat needs far less.
Can any of these run on our own servers?
Two of the nine state self-hosting or on-premises deployment on their own sites. The other seven are presented as hosted products.
Which options mention a free plan?
Four of the nine mention a free plan or free open-source software on their sites. Read each plan's limits before you move a whole team.
Is self-hosting worth it for a small business?
Usually only when a contract, policy or regulator requires it. Someone has to own updates, backups and security, and that's real ongoing work.
How long should a chat trial run?
A week of real conversations is enough to see how threads, notifications and search behave for your team.
What should we export before leaving Mattermost?
Export the channels, files and conversations you must keep, and check what the new tool says it can import before you commit to it.
