Softwr

Databases · head to head

EMQX vs Wattwatchers EMS

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
Wattwatchers EMS logo

Wattwatchers EMS

Energy

Smart building energy management system

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only EMQX has a free tier, so it costs nothing to try first.
  • 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.; Wattwatchers EMS requires hardware installation at each monitoring point, increasing total cost of ownership
  • They diverge on capability: EMQX covers Erlang clustering, Wattwatchers EMS covers Real-time monitoring.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which EMQX and Wattwatchers EMS actually diverge.

Attributes where EMQX and Wattwatchers EMS differ
AttributeEMQXWattwatchers EMS
Starting priceFreeOn request
Pricing modelPer month by connection and session volumeUnknown
Free tierYesNo
PlatformsLinux, Docker, Kubernetes, Cloud, macOSWeb, iOS, Android, Cloud
CategoryDatabasesEnergy
FoundedUnknown2007

Identical on both: user rating (Not yet rated).

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 Wattwatchers EMS

  • Real-time monitoring
  • Energy analytics
  • Smart recommendations
  • Alert system
  • Mobile app
  • Home Assistant
  • Google Home
  • SSL encryption

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

Wattwatchers EMS

  • Energy optimizationnot EMQX
  • Cost reductionnot 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.

Wattwatchers EMS

  • Requires hardware installation at each monitoring point, increasing total cost of ownership
  • Built for small to medium portfolios; scaling to large portfolios may present usability challenges
  • Limited to energy monitoring; not a comprehensive building management system

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

Wattwatchers EMS

On request

No published plan breakdown. See the Wattwatchers EMS review.

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 Wattwatchers EMS if

  • You need real-time monitoring.
  • You work on Web, iOS, Android, Cloud.
  • You also want energy analytics.
Wattwatchers EMS review

Questions people ask

Is EMQX or Wattwatchers EMS better?
Neither clearly leads. EMQX starts at Free and Wattwatchers EMS at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, EMQX or Wattwatchers EMS?
EMQX has a free tier; the other does not. Paid plans start at Free for EMQX and On request for Wattwatchers EMS.
Does EMQX or Wattwatchers EMS run on more platforms?
EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS. Wattwatchers EMS runs on Web, iOS, Android, Cloud.
Can I use EMQX for free?
Yes. EMQX has a free tier, so you can try it without paying. Wattwatchers EMS starts at On request.
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 Wattwatchers EMS is typically brought in for.
What can EMQX do that Wattwatchers EMS cannot?
EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks. Wattwatchers EMS covers Real-time monitoring, Energy analytics, Smart recommendations, Alert system.

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.

Wattwatchers EMS: What data does Wattwatchers monitor?

Wattwatchers measures consumption at the device or circuit level in real-time, identifies equipment inefficiencies, and streams data through cloud dashboards for detailed energy consumption pattern analysis.

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.

Wattwatchers EMS: What web-based tools does Wattwatchers provide?

Wattwatchers provides Fleet Management for fleet overview and device health, an Onboarding tool for smartphone-based device configuration, and a Dashboard for customers to view sites and data.

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.

Wattwatchers EMS: What is the mydata.energy app?

mydata.energy is Wattwatchers' mobile application available on iPhone and Android that provides real-time energy management and monitoring for homes and small businesses.

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.

Wattwatchers EMS: How does ADEPT help with energy management?

ADEPT is Wattwatchers' agile development platform for distributed energy that enables fleet analytics, real-time performance analysis, and zero-code prototyping of custom analytics rules.

Source
Share

Related pages

More on EMQX

More on Wattwatchers EMS

Keep looking

Other head to heads