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Databases · head to head

EMQX vs Estuary

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
Estuary logo

Estuary

Databases

Real-time data integration combining streaming, CDC, and batch

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.; Estuary per-GB pricing adds up quickly for high-volume scenarios
  • They diverge on capability: EMQX covers Erlang clustering, Estuary covers Real-time data delivery.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which EMQX and Estuary actually diverge.

Attributes where EMQX and Estuary differ
AttributeEMQXEstuary
Pricing modelPer month by connection and session volumeUsage-based per GB plus per-connector cost
PlatformsLinux, Docker, Kubernetes, Cloud, macOSCloud, Private Cloud, BYOC
FoundedUnknown2019

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 Estuary

  • Real-time data delivery
  • Change data capture
  • Batch processing
  • Data transformation
  • Pre-built connectors
  • Multiple deployments
  • RBAC and monitoring

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 Estuary
  • An industrial operator routing sensor telemetry straight into TimescaleDB or Kafka without writing a consumer servicenot Estuary
  • An IoT product team that has outgrown a single Mosquitto instance and needs clustering and shared subscriptionsnot Estuary
  • A smart building deployment mixing MQTT, CoAP and LwM2M devices on one brokernot Estuary

Estuary

  • Real-time data replication to data warehousesnot EMQX
  • Change data capture from operational databasesnot EMQX
  • Feeding analytics and BI systems with fresh datanot EMQX
  • Powering real-time AI and ML data pipelinesnot 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.

Estuary

  • Per-GB pricing adds up quickly for high-volume scenarios
  • No transparent per-connector volume discounts below 6 connectors
  • Limited to data movement; transformation capabilities are basic
  • BYOC and private deployment requires enterprise plan
  • Smaller ecosystem compared to established alternatives

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

Estuary

Free
  • DeveloperFree
    • 10 GB per month
    • 2 connector instances maximum
    • No credit card required
  • Cloud$0.5/GB
    • $0.50 per GB of data moved
    • $100 per connector monthly (6+ connectors $50 each)
    • 200+ connectors
  • Enterprise$null/custom
    • Volume-based discounts
    • SOC 2 and HIPAA compliance
    • SSO authentication

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 Estuary if

  • You need real-time data delivery.
  • You want to start without paying.
  • You work on Cloud, Private Cloud, BYOC.
  • You also want change data capture.
Estuary review

Questions people ask

Is EMQX or Estuary better?
Neither clearly leads. EMQX starts at Free and Estuary at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, EMQX or Estuary?
EMQX starts at Free and Estuary at Free.
Does EMQX or Estuary run on more platforms?
EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS. Estuary runs on Cloud, Private Cloud, BYOC.
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 Estuary is typically brought in for.
What can EMQX do that Estuary cannot?
EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks. Estuary covers Real-time data delivery, Change data capture, Batch processing, Data transformation.

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.

Estuary: What is included in the free Developer plan?

Developer plan ($0/month) includes 10 GB of data per month and up to 2 connector instances, no credit card required.

Source
EMQX: Can I run a free cluster?

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

Estuary: How is data pricing calculated on Cloud plan?

Cloud plan charges $0.50 per GB of data moved plus $100/month per connector for the first 6 connectors, then $50/month for additional connectors.

Source
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.

Estuary: What discount is available when adding 6+ connectors?

When using 6 or more connectors, the per-connector cost drops to $50/month from $100/month, saving $50 per additional connector.

Source
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.

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