Databases · head to head
Aiven vs EMQX

EMQX
Databases
Erlang MQTT broker for large IoT fleets, relicensed to BSL with production free use limited to one node
- From
- Free
- Rated
- -
The short version
- Each has a real cost: Aiven the free plan gives 1 VM with 1 CPU, 1 GB RAM and 1 GB storage, and cannot pick a specific cloud or region; 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.
- They diverge on capability: Aiven covers Multi-cloud Support, EMQX covers Erlang clustering.
- Prices and features above were last checked on 31 August 2026.
Where they differ
Only the attributes on which Aiven and EMQX 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 Aiven
- Multi-cloud Support
- Automated Backups
- Seamless Upgrades
- VPC Peering
- End-to-end Encryption
- Compliance
- Observability
- PostgreSQL
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
What people use each for
The jobs each tool is most often brought in to do.
Aiven
- Running managed open source databases without operating themnot EMQX
- Multi-cloud deployment across AWS, Google Cloud, Azure, DigitalOcean, OVH and UpCloudnot EMQX
- Highly available data services with automatic failovernot EMQX
- Prototyping on a small free instance before scaling upnot EMQX
EMQX
- A connected vehicle platform needing millions of persistent MQTT sessions with QUIC for handover across mobile networksnot Aiven
- An industrial operator routing sensor telemetry straight into TimescaleDB or Kafka without writing a consumer servicenot Aiven
- An IoT product team that has outgrown a single Mosquitto instance and needs clustering and shared subscriptionsnot Aiven
- A smart building deployment mixing MQTT, CoAP and LwM2M devices on one brokernot Aiven
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Aiven
- The free plan gives 1 VM with 1 CPU, 1 GB RAM and 1 GB storage, and cannot pick a specific cloud or region
- Free and Developer tiers have no integrations and no connection pooling
- Connection pooling, database forks and dynamic disk sizing need the Business or Premium plan
- A 99.99 percent uptime SLA starts at the Startup plan from $75 a month
- High availability with automatic failover starts at Business from $180 a month
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.
Pricing, plan by plan
Aiven
Free- Free TrialFree
- $300 credits
- 30 day trial
- All services
- Startup$19/month
- Single node
- Basic support
- Daily backups
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
Which should you pick?
Choose Aiven if
- You need multi-cloud support.
- You want to start without paying.
- You work on Web, Aws, Azure, Gcp, Do.
- You also want automated backups.
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.
Questions people ask
- Is Aiven or EMQX better?
- Neither clearly leads. Aiven starts at Free and EMQX at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Aiven or EMQX?
- Aiven starts at Free and EMQX at Free.
- Does Aiven or EMQX run on more platforms?
- Aiven runs on Web, Aws, Azure, Gcp, Do. EMQX runs on Linux, Docker, Kubernetes, Cloud, macOS.
- Can I use Aiven for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Aiven best used for?
- Aiven is most often used for running managed open source databases without operating them, multi-cloud deployment across aws, google cloud, azure, digitalocean, ovh and upcloud, highly available data services with automatic failover, prototyping on a small free instance before scaling up. Of those, running managed open source databases without operating them and multi-cloud deployment across aws, google cloud, azure, digitalocean, ovh and upcloud are not what EMQX is typically brought in for.
- What can Aiven do that EMQX cannot?
- Aiven covers Multi-cloud Support, Automated Backups, Seamless Upgrades, VPC Peering. EMQX covers Erlang clustering, MQTT 5.0 and QUIC, Rule engine, Data integration sinks.
Answered from the vendors’ own pages
Aiven: What does Aiven's free tier include and does it have any time limit?
The free tier includes PostgreSQL with 1 VM, 1 CPU, 1 GB RAM, and 1 GB storage with access to limited cloud and region selections. There are no time limitations on the free tier, though Aiven reserves the right to shut down accounts that violate policies or remain unused for extended periods.
SourceEMQX: 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.
Aiven: How is Aiven billed and what are the monthly costs for each tier?
Aiven bills services by the hour and invoices monthly, charging only for what you actually run. PostgreSQL pricing starts at 5 dollars per month for Developer, 12 dollars per month for Hobbyist, 75 dollars per month for Startup, 180 dollars per month for Business, and 270 dollars per month for Premium. All paid tiers offer hourly billing options as well.
SourceEMQX: Can I run a free cluster?
No. The additional use grant permits free production use of one node; clustering requires a commercial licence.
Aiven: What backup retention periods are included at different Aiven tiers?
Backup retention increases with tier level: Startup tier provides 2 days of backup retention, Business tier offers 14 days, and Premium tier includes 30 days. Point-in-time restore is available on all paid tiers.
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.
Aiven: Is high availability included in Aiven pricing or charged separately?
High availability, backups, and routine maintenance are all included in the tier costs with no separate charges. The Business tier includes 2 VMs with automatic failover, and Premium includes 3 VMs with a second standby node.
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.
Aiven: Does Aiven offer a trial period to test premium features?
Aiven offers a 30-day free trial to access premium features beyond what the free plan provides.
SourceRelated pages
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