Databases · head to head
EMQX vs SurrealDB
EMQX
Databases
Erlang MQTT broker for large IoT fleets, relicensed to BSL with production free use limited to one node
- From
- Free
- Rated
- -
SurrealDB
Databases
Multi-model database combining documents, graphs, vectors and time-series
- From
- Free
- Rated
- -
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.; SurrealDB the listed $0.192/node/hr Scale pricing lacks transparent higher-tier rates, requiring a sales conversation for full production sizing.
- They diverge on capability: EMQX covers Erlang clustering, SurrealDB covers Multi-model engine.
- Prices and features above were last checked on 31 August 2026.
Where they differ
Only the attributes on which EMQX and SurrealDB actually diverge.
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 SurrealDB
- Multi-model engine
- ACID transactions
- Hybrid retrieval
- Horizontal scaling
- Multi-region disaster recovery
- FIPS-compliant cryptography
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 SurrealDB
- An industrial operator routing sensor telemetry straight into TimescaleDB or Kafka without writing a consumer servicenot SurrealDB
- An IoT product team that has outgrown a single Mosquitto instance and needs clustering and shared subscriptionsnot SurrealDB
- A smart building deployment mixing MQTT, CoAP and LwM2M devices on one brokernot SurrealDB
SurrealDB
- AI agent memory and retrieval-augmented generationnot EMQX
- Applications needing documents, graphs and vectors in one databasenot EMQX
- Knowledge graph construction from unstructured datanot EMQX
- Regulated workloads requiring SOC2/ISO27001/HIPAA-eligible hostingnot 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.
SurrealDB
- The listed $0.192/node/hr Scale pricing lacks transparent higher-tier rates, requiring a sales conversation for full production sizing.
- As a newer multi-model database, it has a smaller ecosystem of drivers, ORMs and community tooling than established single-model databases.
- HIPAA compliance is only available as an Enterprise add-on rather than included in standard paid tiers.
- Combining multiple data models in one engine can add query-planning complexity compared to purpose-built single-model databases.
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
SurrealDB
Free- StartFree
- 1 free instance, then from $0.021/hr
- 1GB storage free forever
- Vertical scaling to terabytes
- Scale$0.192/month
- $0.192/node/hr
- Production-grade fault tolerance
- Horizontal scaling to petabytes
- Enterprise$undefined/month
- Self-hosted, custom pricing
- Clustered fault-tolerant deployments
- FIPS-compliant cryptography
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.
Choose SurrealDB if
- You need multi-model engine.
- You want to start without paying.
- You work on web, api, windows, mac, linux.
- You also want acid transactions.
Questions people ask
- Is EMQX or SurrealDB better?
- Neither clearly leads. EMQX starts at Free and SurrealDB at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, EMQX or SurrealDB?
- EMQX starts at Free and SurrealDB at Free.
- Does EMQX or SurrealDB run on more platforms?
- EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS. SurrealDB runs on web, api, windows, mac, linux.
- 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 SurrealDB is typically brought in for.
- What can EMQX do that SurrealDB cannot?
- EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks. SurrealDB covers Multi-model engine, ACID transactions, Hybrid retrieval, 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.
SurrealDB: What does SurrealDB cost?
SurrealDB Cloud's Start plan is free with one free instance (then from $0.021/hr), the Scale plan runs $0.192/node/hr for production workloads, and Enterprise self-hosted deployments use custom pricing.
SourceEMQX: Can I run a free cluster?
No. The additional use grant permits free production use of one node; clustering requires a commercial licence.
SurrealDB: Is there a free plan and what are its limits?
Yes, the Start plan includes one free instance with 1GB of storage free forever and 1GB of outbound data transfer per month, aimed at prototypes and development.
SourceEMQX: 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.
SurrealDB: How is billing handled?
Customers are invoiced monthly based on actual usage in a pay-as-you-go model with no long-term commitments, though commitment-based discounts are available.
SourceEMQX: 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.
Related pages
Other head to heads
- EMQX vs VerneMQ
- EMQX vs RabbitMQ
- EMQX vs NATS
- EMQX vs Solace PubSub+
- EMQX vs Canary Labs
- EMQX vs TIBCO Enterprise Message Service
- EMQX vs TimescaleDB
- EMQX vs Turso
- EMQX vs Chroma
- EMQX vs DuckDB
- EMQX vs Teradata
- EMQX vs Apache Kafka
- EMQX vs Immuta
- EMQX vs MariaDB
- EMQX vs Materialize
- EMQX vs Oracle Database
- EMQX vs MotherDuck
- EMQX vs Vespa
- EMQX vs Zilliz
- EMQX vs ArangoDB
- EMQX vs RavenDB
- EMQX vs Estuary
- EMQX vs QuestDB
- EMQX vs CosmosDB
- EMQX vs DataGrip
- EMQX vs Firebolt
- EMQX vs Google Cloud SQL
- EMQX vs Microsoft SQL Server
- SurrealDB vs VerneMQ
- SurrealDB vs RabbitMQ
- SurrealDB vs NATS
- SurrealDB vs Solace PubSub+
- SurrealDB vs Canary Labs
- SurrealDB vs TIBCO Enterprise Message Service
- SurrealDB vs TimescaleDB
- SurrealDB vs Turso
- SurrealDB vs Chroma
- SurrealDB vs DuckDB
- SurrealDB vs Teradata
- SurrealDB vs Apache Kafka
- SurrealDB vs Immuta
- SurrealDB vs MariaDB
- SurrealDB vs Materialize
- SurrealDB vs Oracle Database
- SurrealDB vs MotherDuck
- SurrealDB vs Vespa
- SurrealDB vs Zilliz
- SurrealDB vs ArangoDB
- SurrealDB vs RavenDB
- SurrealDB vs Estuary
- SurrealDB vs QuestDB
- SurrealDB vs CosmosDB
- SurrealDB vs DataGrip
- SurrealDB vs Firebolt
- SurrealDB vs Google Cloud SQL
- SurrealDB vs Microsoft SQL Server