Softwr

Databases · head to head

EMQX vs LanceDB

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
LanceDB logo

LanceDB

Databases

Embedded retrieval library over the Apache 2.0 Lance columnar format, with proprietary Cloud and Enterprise tiers for serving at scale.

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.; LanceDB the open source build is a library with no network endpoint, authentication or tenancy model, so exposing it to more than one application means writing your own service in front of it and handing every consumer credentials to the bucket.
  • They diverge on capability: EMQX covers Erlang clustering, LanceDB covers Embedded operation.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which EMQX and LanceDB actually diverge.

Attributes where EMQX and LanceDB differ
AttributeEMQXLanceDB
Starting priceFreeOn request
Pricing modelPer month by connection and session volumequote
Free tierYesNo
PlatformsLinux, Docker, Kubernetes, Cloud, macOSWeb

Identical on both: 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 LanceDB

  • Embedded operation
  • Lance columnar format
  • Object storage native
  • Multimodal storage
  • Vector indexes
  • Full-text and hybrid search
  • Scalar filtering
  • Dataset versioning

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

LanceDB

  • Retrieval over a dataset that includes images, audio or video, where keeping the embeddings and the source media in one format avoids a second storage systemnot EMQX
  • A training and retrieval pipeline that must read the same rows for both purposes without maintaining two copies and a sync jobnot EMQX
  • Prototyping search locally with the same code path that later runs against S3, with no local server to installnot EMQX
  • Keeping a large, mostly cold vector corpus on object storage rather than paying to hold it in memory in a conventional vector databasenot 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.

LanceDB

  • The open source build is a library with no network endpoint, authentication or tenancy model, so exposing it to more than one application means writing your own service in front of it and handing every consumer credentials to the bucket.
  • Queries that miss the cache pay object storage round trips, so interactive latency depends on local SSD caching or the Enterprise serving tier rather than on the library itself.
  • Concurrent writers to the same dataset coordinate through commits on the object store, so multi-writer setups can conflict and the safe pattern is a single writer per table, which is an architectural constraint on your ingest design.
  • Newly written rows are not in the index until the index is rebuilt or updated, and until then they are searched by brute force, so recall and latency drift between reindexing jobs that you have to schedule and pay for.
  • The capabilities that make it operable at scale, distributed index building, managed caching and hosted serving, live in the proprietary Cloud and Enterprise tiers, so the open licence protects the data but not the production deployment.

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

LanceDB

On request

No published plan breakdown. See the LanceDB 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 LanceDB if

  • You need embedded operation.
  • You also want lance columnar format.
LanceDB review

Questions people ask

Is EMQX or LanceDB better?
Neither clearly leads. EMQX starts at Free and LanceDB at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, EMQX or LanceDB?
EMQX has a free tier; the other does not. Paid plans start at Free for EMQX and On request for LanceDB.
Does EMQX or LanceDB run on more platforms?
EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS. LanceDB runs on Web.
Can I use EMQX for free?
Yes. EMQX has a free tier, so you can try it without paying. LanceDB 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 LanceDB is typically brought in for.
What can EMQX do that LanceDB cannot?
EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks. LanceDB covers Embedded operation, Lance columnar format, Object storage native, Multimodal storage.

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.

LanceDB: Is LanceDB open source?

The LanceDB library and the underlying Lance format are Apache 2.0. LanceDB Cloud and LanceDB Enterprise are proprietary managed products built on top of them.

EMQX: Can I run a free cluster?

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

LanceDB: Do I need the managed service?

Not for development or for embedded use in a single application. You typically need it when many clients must query concurrently with predictable latency, or when index builds outgrow one machine.

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.

LanceDB: Can other tools read my data?

Yes. Lance datasets are readable from DuckDB, Polars, Pandas, PyArrow and PyTorch, which is the main practical difference from a vector database that owns its own storage.

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.

LanceDB: How does it compare to pgvector?

pgvector keeps vectors next to relational data in a database you already run. LanceDB keeps them in object storage in a format built for random access and multimodal payloads, and scales storage independently of any server.

LanceDB: What happens to updates and deletes?

Writes append new fragments and mark old rows deleted, with compaction reclaiming space later, so a workload with heavy in-place updates accumulates overhead until compaction runs.

Share

Related pages

More on EMQX

More on LanceDB

Keep looking

Other head to heads