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Databases · head to head

EMQX vs RisingWave

EMQX logo

EMQX

Databases

Erlang MQTT broker for large IoT fleets, relicensed to BSL with production free use limited to one node

From
Free
Rated
-
Full reviewWebsite
RisingWave logo

RisingWave

Databases

Streaming database that maintains incremental materialised views in SQL instead of Flink jobs

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: EMQX the move to Business Source Licence 1.1 at version 5.9 in May 2025 limits free production use to a single node, so the clustering that justifies choosing EMQX now requires a paid subscription from the second node onward.; RisingWave anything that does not fit SQL, such as custom windowing, complex event processing or heavy stateful logic, still needs Flink, so RisingWave often adds a system rather than removing one.
  • They diverge on capability: EMQX covers Erlang clustering, RisingWave covers SQL materialised views.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which EMQX and RisingWave actually diverge.

Attributes where EMQX and RisingWave differ
AttributeEMQXRisingWave
Pricing modelPer month by connection and session volumePer RisingWave Unit hour
PlatformsLinux, Docker, Kubernetes, Cloud, macOSLinux, Docker, Kubernetes, Cloud

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Databases).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in EMQX

  • Erlang clustering
  • MQTT 5.0 and QUIC
  • Rule engine
  • Data integration sinks
  • Session persistence
  • Multi protocol gateways
  • Authentication and authorisation
  • Dashboard and REST API

Only in RisingWave

  • SQL materialised views
  • Postgres wire compatibility
  • Object storage state
  • Source connectors
  • Sink connectors
  • Iceberg tables
  • Watermarks and windowing
  • User defined functions

What people use each for

The jobs each tool is most often brought in to do.

EMQX

  • A connected vehicle platform needing millions of persistent MQTT sessions with QUIC for handover across mobile networksnot RisingWave
  • An industrial operator routing sensor telemetry straight into TimescaleDB or Kafka without writing a consumer servicenot RisingWave
  • An IoT product team that has outgrown a single Mosquitto instance and needs clustering and shared subscriptionsnot RisingWave
  • A smart building deployment mixing MQTT, CoAP and LwM2M devices on one brokernot RisingWave

RisingWave

  • A team with Kafka topics that needs continuously fresh aggregates for a dashboard without standing up a Flink clusternot EMQX
  • A fraud or risk team maintaining rolling counters and joins across event streams expressed as SQL viewsnot EMQX
  • A company doing Postgres CDC into a real-time denormalised view for search or servingnot EMQX
  • An analytics group that wants streaming results landed directly into Apache Iceberg without a separate writer jobnot EMQX

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

EMQX

  • The move to Business Source Licence 1.1 at version 5.9 in May 2025 limits free production use to a single node, so the clustering that justifies choosing EMQX now requires a paid subscription from the second node onward.
  • The relicensing arrived in a minor release, which caught users who had pinned to 5.x expecting Apache 2.0 terms and forced legal review of existing deployments.
  • Running an Erlang/OTP cluster well requires operational knowledge most teams do not have, and diagnosing distribution, mnesia or memory issues means learning a runtime you use for nothing else.
  • Enterprise pricing is quoted rather than published for the self-managed edition, so the cost of the clustered configuration you actually need is invisible until you talk to sales.
  • The Serverless tier caps at around a thousand connections and shares infrastructure, which makes it a prototyping tier rather than a genuine small production option.

RisingWave

  • Anything that does not fit SQL, such as custom windowing, complex event processing or heavy stateful logic, still needs Flink, so RisingWave often adds a system rather than removing one.
  • The Apache 2.0 community edition excludes premium features behind a licence key, and which capabilities sit on which side of that line moves between releases, so a self-hosted plan can be invalidated by an upgrade.
  • Long-running materialised views accumulate state in object storage, and cost and recovery time grow with retention in ways that are hard to forecast before you are in production.
  • The Postgres compatibility is protocol level; it is not a transactional Postgres and using it as a general purpose database, with point updates or high write concurrency, goes badly.
  • It is a comparatively young venture-funded project competing with Flink, Materialize and warehouse-native streaming, and the ecosystem of connectors, operators and third-party expertise is much thinner.

Pricing, plan by plan

EMQX

Free
  • Open Source single nodeFree
    • BSL 1.1 licence since version 5.9
    • Free production use of one node only
    • All former enterprise features visible
  • ServerlessFree
    • Free monthly quota then pay as you go
    • Up to 1,000 connections
    • 8 by 5 support
  • Dedicated Flex$234/month
    • Single tenant cluster
    • Traffic allowance included
    • 24/7 support
  • Enterprise self-managed$undefined/year
    • Deploy on premises, at the edge or in any cloud
    • Clustering licensed
    • 256 MB maximum message size

RisingWave

Free
  • Community EditionFree
    • Apache 2.0 licence, self-hosted
    • Core streaming engine and connectors
    • Premium features excluded and require a licence key
  • Cloud Basic$0.227/hour
    • Billed per RisingWave Unit hour
    • Hosted on AWS, GCP or Azure
    • Capped at 64 cores
  • Cloud Pro$undefined/year
    • No core limit
    • Bring your own cloud option
    • Premium features included
  • Self-managed Enterprise$undefined/year
    • On premises or Kubernetes
    • Premium features unlocked by licence
    • Annual contract with SLA

Which should you pick?

Choose EMQX if

  • You need erlang clustering.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Cloud, macOS.
  • You also want mqtt 5.0 and quic.
EMQX review

Choose RisingWave if

  • You need sql materialised views.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Cloud.
  • You also want postgres wire compatibility.
RisingWave review

Questions people ask

Is EMQX or RisingWave better?
Neither clearly leads. EMQX starts at Free and RisingWave at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, EMQX or RisingWave?
EMQX starts at Free and RisingWave at Free.
Does EMQX or RisingWave run on more platforms?
EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS. RisingWave runs on Linux, Docker, Kubernetes, Cloud.
Can I use EMQX for free?
Both have a free tier, so you can try either at no cost before committing.
What is EMQX best used for?
EMQX is most often used for a connected vehicle platform needing millions of persistent mqtt sessions with quic for handover across mobile networks, an industrial operator routing sensor telemetry straight into timescaledb or kafka without writing a consumer service, an iot product team that has outgrown a single mosquitto instance and needs clustering and shared subscriptions, a smart building deployment mixing mqtt, coap and lwm2m devices on one broker. Of those, a connected vehicle platform needing millions of persistent mqtt sessions with quic for handover across mobile networks and an industrial operator routing sensor telemetry straight into timescaledb or kafka without writing a consumer service are not what RisingWave is typically brought in for.
What can EMQX do that RisingWave cannot?
EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks. RisingWave covers SQL materialised views, Postgres wire compatibility, Object storage state, Source connectors.

Answered from the vendors’ own pages

EMQX: Is EMQX still open source?

Not in the OSI sense since version 5.9. It is source-available under Business Source Licence 1.1, reverting to Apache 2.0 four years after each release.

RisingWave: Is RisingWave open source?

The community edition is Apache 2.0 and self-hostable, but a set of premium features requires a paid licence key.

EMQX: Can I run a free cluster?

No. The additional use grant permits free production use of one node; clustering requires a commercial licence.

RisingWave: What does the cloud cost?

It starts at 0.227 US dollars per RisingWave Unit hour on the Basic tier, which is capped at 64 cores.

EMQX: What changed for existing users?

Community and enterprise editions merged, so all features are now visible, but the licence terms tightened in the same minor release.

RisingWave: Does it replace Flink?

For SQL-expressible transformations, often yes. For custom stateful processing and complex event handling, no.

EMQX: Which version is still Apache 2.0?

Releases before 5.9 remain under Apache 2.0, and each BSL release converts to Apache 2.0 four years after publication.

RisingWave: Can I query it like Postgres?

Yes over the Postgres wire protocol, but it is an analytical streaming engine, not a transactional database.

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