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Databases · head to head

EMQX vs PlanetScale

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
PlanetScale logo

PlanetScale

Databases

The MySQL-compatible serverless database

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.; PlanetScale pricing varies significantly across 17+ AWS and GCP regions
  • They diverge on capability: EMQX covers Erlang clustering, PlanetScale covers Database Branching.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which EMQX and PlanetScale actually diverge.

Attributes where EMQX and PlanetScale differ
AttributeEMQXPlanetScale
Pricing modelPer month by connection and session volumeusage-based
PlatformsLinux, Docker, Kubernetes, Cloud, macOSCloud-hosted (AWS, GCP, Azure)
FoundedUnknown2018

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 PlanetScale

  • Database Branching
  • Non-blocking Schema Changes
  • Insights
  • Horizontal Scaling
  • Connection Pooling
  • Query Caching
  • Automatic Backups
  • Global Replication

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

PlanetScale

  • MySQL-compatible applications requiring horizontal scalingnot EMQX
  • PostgreSQL deployments with custom cluster configurationsnot EMQX
  • Multi-region database deployments on AWS or GCPnot EMQX
  • Applications requiring transparent sharding via Vitessnot 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.

PlanetScale

  • Pricing varies significantly across 17+ AWS and GCP regions
  • Additional costs for EBS storage beyond base tier, backup storage, and egress
  • Dedicated PgBouncer and replicas incur separate charges
  • Metal tier pricing increases sharply with larger configurations

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

PlanetScale

Free
  • Postgres EBS Single-Node (ARM64 PS-5)$5/month
    • 512 MiB RAM
    • Single-node configuration
    • EBS storage included
  • Postgres EBS HA (ARM64 PS-5)$15/month
    • 512 MiB RAM
    • 3-node high-availability setup
    • 1 primary + 2 replicas
  • Postgres Metal (M-10)$50/month
    • 1/8 vCPU, 1 GiB RAM
    • 3-node HA configuration
    • 10 GiB NVMe storage included
  • Vitess Non-Metal 3-Node$39/month
    • Sharding-capable database
    • x86-64 architecture
    • 3-node configuration

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 PlanetScale if

  • You need database branching.
  • You want to start without paying.
  • You work on Cloud-hosted (AWS, GCP, Azure).
  • You also want non-blocking schema changes.
PlanetScale review

Questions people ask

Is EMQX or PlanetScale better?
Neither clearly leads. EMQX starts at Free and PlanetScale at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, EMQX or PlanetScale?
EMQX starts at Free and PlanetScale at Free.
Does EMQX or PlanetScale run on more platforms?
EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS. PlanetScale runs on Cloud-hosted (AWS, GCP, Azure).
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 PlanetScale is typically brought in for.
What can EMQX do that PlanetScale cannot?
EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks. PlanetScale covers Database Branching, Non-blocking Schema Changes, Insights, Horizontal Scaling.

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.

PlanetScale: How much does a PlanetScale Postgres database cost per month?

PlanetScale Postgres pricing starts at $5/month for single-node ARM64 configurations with 512 MiB RAM and $15/month for the same specs in high-availability mode with 1 primary and 2 replicas. Metal tier starts at $50/month for M-10 configuration (1/8 vCPU, 1 GiB RAM). Exact pricing depends on cluster size, node architecture (ARM64 vs x86-64), storage configuration, and selected AWS/GCP region.

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.

PlanetScale: Is there a free tier for PlanetScale?

PlanetScale offers a free tier for development and testing workloads. After free tier limits are reached, usage-based pricing applies starting at $5/month for the smallest Postgres single-node configuration, with costs scaling based on cluster size, compute, storage, and additional features like dedicated PgBouncer or replicas.

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.

PlanetScale: What is the difference between PlanetScale ARM64 and x86-64 pricing?

ARM64 instances cost significantly less than x86-64 equivalents. For example, a Postgres EBS HA cluster with 512 MiB RAM costs $15/month on ARM64 but $39/month on x86-64. This pricing difference extends across all cluster sizes, with larger x86-64 configurations reaching up to $5,599/month compared to ARM64 alternatives.

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.

PlanetScale: What is included in a PlanetScale cluster price versus additional costs?

The advertised cluster price covers the base compute and configured storage. Additional charges apply for EBS storage beyond the base allocation, backup storage, data egress, optional dedicated PgBouncer connections, and replicas beyond the base high-availability configuration. Regional pricing varies across 17+ AWS and GCP zones.

Source
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