Rocket.Chat is the maximalist of open source team chat. Messaging, voice, video, screen sharing, omnichannel customer support, a marketplace of apps, LDAP, federation — it does an enormous amount, and it needs an enormous amount to do it. Fluid Chat is the opposite bet: one thing, done completely, on the smallest stack that can hold it.
The one-paragraph answer
Choose Rocket.Chat if you need voice and video in the same product as your chat, if you're doing customer-facing omnichannel support, if you want a marketplace of prebuilt integrations, or if federation matters. Choose Fluid Chat if you want team messaging and nothing else, on Postgres, with every admin feature included at $0 and a fraction of the operational surface.
The MongoDB question
The most consequential difference between these two isn't a feature — it's the datastore. Rocket.Chat is built on MongoDB. Fluid is built on Postgres. If you already operate one of those confidently and not the other, that fact alone is probably enough to decide this.
What it means practically:
- Backups and restores look different. A
pg_dumpis a well-trodden path with tooling on every ops team's shelf; MongoDB backups are perfectly fine but a separate skill set. - Ad-hoc querying. Wanting to answer “how many messages did #incidents get last quarter” with SQL is a real convenience, and Postgres gives it to you for free.
- Search. Fluid keeps full-text search inside Postgres. Rocket.Chat can use MongoDB text search and commonly pairs with Elasticsearch at scale — that's another service to run.
- Managed hosting. Managed Postgres is available from essentially every provider at every price point. Managed MongoDB is available, just from fewer places.
Where they differ
| Fluid Chat | Rocket.Chat | |
|---|---|---|
| Backend | TypeScript / Next.js 15 | JavaScript / Meteor |
| Database | Postgres | MongoDB |
| Search | Postgres full-text | MongoDB text, or Elasticsearch |
| Voice / video / screen share | No | Yes |
| Omnichannel customer support | No | Yes |
| App marketplace | No | Yes |
| Federation | No | Yes (Matrix) |
| Native mobile apps | No (responsive web) | iOS and Android |
| Admin features gated by tier | None | Some |
| Pricing model | $0, hosted or self-hosted | Free tier plus paid plans |
| Services to operate | App, realtime, worker, Postgres | App, MongoDB, often Elasticsearch and more |
Rocket.Chat has revised its free and Community plan terms more than once over the years, including user limits on some tiers — check rocket.chat/pricing for the current position rather than trusting any comparison table, including this one.
Feature breadth versus feature depth
It's easy to read a comparison table and conclude that more rows with “Yes” is better. That's true right up until you're the person running it.
Rocket.Chat's breadth is genuinely valuable if you use it. If you're running a support desk that talks to customers over WhatsApp, email and web chat and you want that in the same place as your internal channels, there is essentially nothing else that does it as an open source, self-hosted deployment. That is a real superpower.
If you're not doing that, you're operating a platform sized for it anyway. Fluid's scope — messaging, threads, search, files, admin, API, and no calls — is a smaller promise, and the payoff is that the whole thing runs on one Postgres and can be read end to end.
What Fluid includes that usually costs money
Since both products have a free path, the interesting comparison is what sits inside free. Fluid's answer is everything:
- Audit log and message retention policies.
- Roles — owner, admin, member, guest — with guests scoped to their own channels.
- Per-channel posting policy and per-workspace read-only mode.
- API keys with explicit scopes, per-key rate limits, rotation, expiry and audited creation.
- Full data export — JSONL, CSV and a file manifest.
- Unlimited people, messages, channels, integrations and history.
And what it doesn't have, stated plainly: no voice, video or huddles, no SSO/SAML, no native mobile apps, no federation, no marketplace, and no Slack importer yet.
One database. One product. No marketplace to browse.
If “team chat, complete, on Postgres” is the whole requirement, Fluid is about two minutes from running.
Best Rocket.Chat alternatives, briefly
- 1Fluid Chat — if you want messaging only, on Postgres, with nothing tiered.
- 2Mattermost — if you want the enterprise story, native apps and commercial support, and paid tiers are acceptable.
- 3Zulip — if the real problem is that channel-plus-thread conversations don't scale for your team.
- 4Element / Matrix — if federation was the reason you were looking at Rocket.Chat in the first place.