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Cloud · head to head

Flux vs VerneMQ

Flux logo

Flux

Cloud

GitOps continuous delivery for Kubernetes

From
Free
Rated
-
Full reviewWebsite
VerneMQ logo

VerneMQ

Databases

Erlang MQTT broker whose source is Apache 2.0 but whose official binaries need a paid subscription

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Flux no user interface of its own: observing what Flux is doing means CLI or a third-party dashboard; VerneMQ the official binaries and Docker images are not Apache 2.0 but sit under a EULA requiring a yearly commercial subscription, a distinction easy to miss and awkward to discover during a licence audit.
  • They diverge on capability: Flux covers Git as source of truth, VerneMQ covers Erlang/OTP clustering.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Flux and VerneMQ actually diverge.

Attributes where Flux and VerneMQ differ
AttributeFluxVerneMQ
Pricing modelOpen source, no licence feequote
PlatformsKubernetes, LinuxLinux, Docker, macOS, Kubernetes
CategoryCloudDatabases

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 Flux

  • Git as source of truth
  • Pull-based delivery
  • Helm and Kustomize support
  • Automated image updates

Only in VerneMQ

  • Erlang/OTP clustering
  • MQTT 5.0 support
  • Plugin system
  • Backpressure handling
  • Bridge support
  • Metrics export
  • MQTT over WebSockets
  • Pluggable auth backends

What people use each for

The jobs each tool is most often brought in to do.

Flux

  • Removing cluster credentials from CI systemsnot VerneMQ
  • Keeping many clusters consistent with a single declared statenot VerneMQ
  • Automatically correcting configuration drift rather than discovering it laternot VerneMQ

VerneMQ

  • An industrial operator that wants an MQTT broker with predictable memory behaviour and no data integration features it will not usenot Flux
  • A team building from source to stay strictly under Apache 2.0 terms with no vendor licence entanglementnot Flux
  • A deployment needing custom authentication logic implemented as a plugin in Lua or over a webhooknot Flux
  • An organisation that wants a broker maintained by a small European company rather than by a vendor that keeps changing licencesnot Flux

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Flux

  • No user interface of its own: observing what Flux is doing means CLI or a third-party dashboard
  • Debugging a stuck reconciliation is harder than reading a pipeline log, because failure is asynchronous
  • Everything must be in Git, which is awkward for secrets and needs a sealed-secrets or external-secrets approach
  • GitOps is a workflow change, not just a tool, and teams used to imperative deploys find the adjustment real

VerneMQ

  • The official binaries and Docker images are not Apache 2.0 but sit under a EULA requiring a yearly commercial subscription, a distinction easy to miss and awkward to discover during a licence audit.
  • Octavo Labs is a very small company, so support depth, response times and the bus factor on the codebase are materially thinner than at HiveMQ or EMQ.
  • There is no data integration or rule engine layer, so routing messages into a database means writing and operating your own consumer service.
  • Operating an Erlang cluster requires runtime knowledge that most teams do not have and will use for nothing else in their stack.
  • There is no vendor-managed cloud offering, so every deployment is self-operated with the infrastructure and on-call cost that implies.

Pricing, plan by plan

Flux

Free
  • FluxFree
    • Full functionality
    • No usage limits
    • Community support

VerneMQ

Free
  • Source buildFree
    • Apache 2.0 licensed source from GitHub
    • Full clustering and plugin capability
    • You compile and package it yourself
  • Binary packages and Docker images$undefined/year
    • Covered by the VerneMQ EULA, not Apache 2.0
    • Yearly usage subscription expected for commercial use
    • Official builds and Docker images
  • Commercial support$undefined/year
    • Evaluation, customisation and operations assistance
    • Custom development
    • Long-term maintenance agreements

Which should you pick?

Choose Flux if

  • You need git as source of truth.
  • You want to start without paying.
  • You work on Kubernetes, Linux.
  • You also want pull-based delivery.
Flux review

Choose VerneMQ if

  • You need erlang/otp clustering.
  • You want to start without paying.
  • You work on Linux, Docker, macOS, Kubernetes.
  • You also want mqtt 5.0 support.
VerneMQ review

Questions people ask

Is Flux or VerneMQ better?
Neither clearly leads. Flux starts at Free and VerneMQ at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Flux or VerneMQ?
Flux starts at Free and VerneMQ at Free.
Does Flux or VerneMQ run on more platforms?
Flux runs on Kubernetes, Linux. VerneMQ runs on Linux, Docker, macOS, Kubernetes.
Can I use Flux for free?
Both have a free tier, so you can try either at no cost before committing.
What is Flux best used for?
Flux is most often used for removing cluster credentials from ci systems, keeping many clusters consistent with a single declared state, automatically correcting configuration drift rather than discovering it later. Of those, removing cluster credentials from ci systems and keeping many clusters consistent with a single declared state are not what VerneMQ is typically brought in for.
What can Flux do that VerneMQ cannot?
Flux covers Git as source of truth, Pull-based delivery, Helm and Kustomize support, Automated image updates. VerneMQ covers Erlang/OTP clustering, MQTT 5.0 support, Plugin system, Backpressure handling.

Answered from the vendors’ own pages

Flux: Is Flux free?

Yes, open source and CNCF-graduated.

VerneMQ: Is VerneMQ free?

The source is Apache 2.0 and free. The official binary packages and Docker images are covered by a separate EULA that expects a yearly fee for commercial use.

Flux: Flux or Argo CD?

Both implement GitOps. Argo CD ships a strong web UI and is often preferred for visibility; Flux is more modular and composes as controllers, which suits platform teams.

VerneMQ: Is the project still maintained?

Yes. Octavo Labs AG in Zurich continues to publish 2.x releases, most recently in 2026.

Flux: Why is pull-based safer?

Because the cluster reaches out to Git rather than CI reaching into the cluster. No external system needs write credentials to production.

VerneMQ: Does it have a managed cloud?

No. Every deployment is self-hosted, with commercial support available from Octavo Labs.

VerneMQ: How does it compare to EMQX?

Narrower in features and without a rule engine, but with a simpler licence story for source builds after EMQX moved to BSL.

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