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Databases · head to head

EMQX vs PubNub

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
PubNub logo

PubNub

APIs

Realtime communication platform for chat, IoT, and live data apps

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.; PubNub free plan storage history is limited to 7 days, which is short for apps needing longer message retention.
  • They diverge on capability: EMQX covers Erlang clustering, PubNub covers Pub/sub messaging.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which EMQX and PubNub actually diverge.

Attributes where EMQX and PubNub differ
AttributeEMQXPubNub
Pricing modelPer month by connection and session volumefreemium
PlatformsLinux, Docker, Kubernetes, Cloud, macOSweb, ios, android, api
CategoryDatabasesAPIs

Identical on both: starting price (Free), free tier (Yes), 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 PubNub

  • Pub/sub messaging
  • Presence tracking
  • Message persistence
  • Serverless Functions
  • File sharing
  • Encryption and access controls

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

PubNub

  • Building realtime chat applicationsnot EMQX
  • Streaming live IoT sensor datanot EMQX
  • Adding presence indicators to collaborative appsnot EMQX
  • Running edge logic with serverless Functions on realtime eventsnot 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.

PubNub

  • Free plan storage history is limited to 7 days, which is short for apps needing longer message retention.
  • MAU-based pricing means costs scale directly with user growth, which can be less predictable than flat message-based pricing.
  • Pro-tier custom pricing above 50,000 MAU requires contacting sales rather than self-serve checkout.

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

PubNub

Free
  • FreeFree
    • Up to 200 MAU or 1M transactions
    • 1GB data storage (7 days)
    • 5 test Serverless Functions
  • Starter$98/month
    • 1,000 MAU included
    • User management
    • Insights
  • Pro$undefined/month
    • Custom MAU packages
    • Volume discounts
    • Enterprise-scale configurations

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 PubNub if

  • You need pub/sub messaging.
  • You want to start without paying.
  • You work on web, ios, android, api.
  • You also want presence tracking.
PubNub review

Questions people ask

Is EMQX or PubNub better?
Neither clearly leads. EMQX starts at Free and PubNub at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, EMQX or PubNub?
EMQX starts at Free and PubNub at Free.
Does EMQX or PubNub run on more platforms?
EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS. PubNub runs on web, ios, android, api.
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 PubNub is typically brought in for.
What can EMQX do that PubNub cannot?
EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks. PubNub covers Pub/sub messaging, Presence tracking, Message persistence, Serverless Functions.

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.

PubNub: What does PubNub cost?

PubNub offers a free plan for up to 200 MAU or 1 million transactions, a Starter plan at $98/month for 1,000 MAU, and custom Pro pricing for larger volumes, e.g. around $550/month for 10,000 MAU.

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.

PubNub: Is there a free plan, and what are its limits?

Yes, the free plan supports up to 200 monthly active users or 1 million transactions, includes 1GB of data storage retained for 7 days, and requires no credit card.

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.

PubNub: How is usage metered?

PubNub bills primarily by Monthly Active Users, defined as a unique user who connects at least once in a billing cycle; messages are bundled into MAU pricing with no separate per-message fees, and overage is billed proportionally.

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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