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Databases · head to head

EMQX vs Vespa

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
Vespa logo

Vespa

Databases

Distributed AI search platform for retrieval, ranking, and inference

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.; Vespa pricing not publicly listed, requires contacting sales
  • They diverge on capability: EMQX covers Erlang clustering, Vespa covers Vector search.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which EMQX and Vespa actually diverge.

Attributes where EMQX and Vespa differ
AttributeEMQXVespa
Pricing modelPer month by connection and session volumecontact-sales
PlatformsLinux, Docker, Kubernetes, Cloud, macOSCloud, Self-hosted
FoundedUnknown2023

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 Vespa

  • Vector search
  • Text and structured search
  • Machine-learned ranking
  • Real-time serving
  • SQL interface
  • Automatic scaling
  • Open-source

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

Vespa

  • Build RAG systems with semantic search over documentsnot EMQX
  • Power e-commerce search with ML rankingnot EMQX
  • Create recommendation engines for personalizationnot EMQX
  • Implement real-time search for news or feedsnot EMQX
  • Deploy private semantic search over sensitive datanot 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.

Vespa

  • Pricing not publicly listed, requires contacting sales
  • Steeper learning curve compared to simpler search tools
  • Operational complexity for self-hosted deployments
  • Smaller ecosystem compared to cloud-native 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

Vespa

Free

No published plan breakdown. See the Vespa 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 Vespa if

  • You need vector search.
  • You want to start without paying.
  • You work on Cloud, Self-hosted.
  • You also want text and structured search.
Vespa review

Questions people ask

Is EMQX or Vespa better?
Neither clearly leads. EMQX starts at Free and Vespa at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, EMQX or Vespa?
EMQX starts at Free and Vespa at Free.
Does EMQX or Vespa run on more platforms?
EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS. Vespa runs on Cloud, Self-hosted.
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 Vespa is typically brought in for.
What can EMQX do that Vespa cannot?
EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks. Vespa covers Vector search, Text and structured search, Machine-learned ranking, Real-time serving.

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.

Vespa: Is Vespa open-source?

Yes, Vespa is open-source under the Apache 2.0 license. The code is available on GitHub, and you can self-host or use the managed cloud service.

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.

Vespa: What latency can Vespa achieve?

Vespa is designed for sub-100 millisecond latencies with thousands of queries per second, suitable for real-time search and recommendation applications.

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.

Vespa: Does Vespa support vector search?

Yes, Vespa provides native vector search capabilities alongside text, structured data, and tensor operations for building comprehensive search and AI applications.

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.

Vespa: What is the pricing model for Vespa Cloud?

Vespa Cloud pricing is not publicly listed and requires contacting their sales team to discuss your specific use case and scale requirements.

Source
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