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Databases · head to head

Apache Pulsar vs Formance

Apache Pulsar logo

Apache Pulsar

Databases

Cloud-native messaging and streaming with separated storage

From
Free
Rated
-
Full reviewWebsite
Formance logo

Formance

APIs

Open source double-entry ledger and payment orchestration for money-moving software

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Apache Pulsar more components than Kafka: brokers, BookKeeper and ZooKeeper each need operating; Formance formance holds no money and provides no regulatory cover, so it must be paired with a payments provider or bank, and buyers occasionally mistake a ledger for a treasury system and discover the gap late.
  • They diverge on capability: Apache Pulsar covers Separated storage, Formance covers Double-entry ledger.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Apache Pulsar and Formance actually diverge.

Attributes where Apache Pulsar and Formance differ
AttributeApache PulsarFormance
PlatformsLinux, Docker, Kubernetes, Self-hostedLinux, Docker, Kubernetes, Web, API
CategoryDatabasesAPIs

Identical on both: starting price (Free), pricing model (Open source, no licence fee), 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 Apache Pulsar

  • Separated storage
  • Queuing and streaming
  • Built-in multi-tenancy
  • Geo-replication

Only in Formance

  • Double-entry ledger
  • Numscript transaction DSL
  • Multi-currency
  • Payments connectivity
  • Reconciliation
  • Self-hosted deployment
  • Cloud offering
  • API and SDKs

What people use each for

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

Apache Pulsar

  • Platforms needing both work queues and replayable streams without running two systemsnot Formance
  • Multi-tenant messaging where isolation between teams is a requirementnot Formance
  • Deployments where storage and traffic grow at genuinely different ratesnot Formance

Formance

  • A marketplace splitting a single customer payment between seller, platform fee and tax that needs the split to be atomic and auditablenot Apache Pulsar
  • A fintech whose homegrown balances table produced numbers finance could not reconcile and now needs proper double-entry before an auditnot Apache Pulsar
  • A payments team that wants one normalised model across several PSPs so reconciliation is not written separately for eachnot Apache Pulsar
  • A company that wants its ledger under a licence it can keep running even if the vendor disappearsnot Apache Pulsar

Where each one falls short

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

Apache Pulsar

  • More components than Kafka: brokers, BookKeeper and ZooKeeper each need operating
  • Correspondingly harder to run well, and the expertise is rarer than Kafka expertise
  • A much smaller ecosystem of connectors, tooling and hiring pool than Kafka
  • The architectural advantages only pay off at a scale most deployments never reach

Formance

  • Formance holds no money and provides no regulatory cover, so it must be paired with a payments provider or bank, and buyers occasionally mistake a ledger for a treasury system and discover the gap late.
  • Numscript is a domain-specific language your team must learn, and while it makes complex splits expressible it also means transaction logic sits outside the languages your engineers already debug well.
  • Self-hosting a ledger that must never lose or duplicate a transaction is a serious operational commitment covering backups, upgrades and Postgres tuning, which is real cost the zero licence fee hides.
  • Enterprise pricing is not published, so the difference between the free path and the supported path cannot be evaluated without a sales conversation.
  • The company is much smaller than the incumbent alternatives, and while the MIT licence protects the code it does not protect the roadmap, so features on the hosted side may arrive slowly or change direction.

Pricing, plan by plan

Apache Pulsar

Free
  • Apache PulsarFree
    • Full functionality
    • No usage limits
    • Community support

Formance

Free
  • Open SourceFree
    • MIT licensed core ledger
    • Numscript transaction DSL
    • Multi-currency tracking
  • Enterprise$undefined/year
    • Managed or private deployment
    • Payments connectivity and reconciliation
    • Support with response commitments

Which should you pick?

Choose Apache Pulsar if

  • You need separated storage.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want queuing and streaming.
Apache Pulsar review

Choose Formance if

  • You need double-entry ledger.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Web, API.
  • You also want numscript transaction dsl.
Formance review

Questions people ask

Is Apache Pulsar or Formance better?
Neither clearly leads. Apache Pulsar starts at Free and Formance at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Apache Pulsar or Formance?
Apache Pulsar starts at Free and Formance at Free.
Does Apache Pulsar or Formance run on more platforms?
Apache Pulsar runs on Linux, Docker, Kubernetes, Self-hosted. Formance runs on Linux, Docker, Kubernetes, Web, API.
Can I use Apache Pulsar for free?
Both have a free tier, so you can try either at no cost before committing.
What is Apache Pulsar best used for?
Apache Pulsar is most often used for platforms needing both work queues and replayable streams without running two systems, multi-tenant messaging where isolation between teams is a requirement, deployments where storage and traffic grow at genuinely different rates. Of those, platforms needing both work queues and replayable streams without running two systems and multi-tenant messaging where isolation between teams is a requirement are not what Formance is typically brought in for.
What can Apache Pulsar do that Formance cannot?
Apache Pulsar covers Separated storage, Queuing and streaming, Built-in multi-tenancy, Geo-replication. Formance covers Double-entry ledger, Numscript transaction DSL, Multi-currency, Payments connectivity.

Answered from the vendors’ own pages

Apache Pulsar: Is Apache Pulsar free?

Yes, open source under the Apache Software Foundation.

Formance: Is Formance really open source?

Yes. The core ledger is MIT licensed with full source access and no deployment restrictions.

Apache Pulsar: Pulsar or Kafka?

Pulsar separates storage from compute and covers queuing and streaming in one system. Kafka has a far larger ecosystem and hiring pool. Most teams should have a specific reason before choosing Pulsar.

Formance: Does Formance move money?

No. It records and orchestrates movements; the actual payments happen at a PSP or bank you connect.

Apache Pulsar: Why does separated storage matter?

Brokers hold no data, so adding or replacing one requires no rebalancing, and storage can grow without adding serving capacity.

Formance: What does the enterprise version cost?

Not published. It is an annual subscription quoted per customer.

Formance: Do I have to use Numscript?

Yes for anything beyond the simplest transfers. It is how multi-party transactions are expressed atomically.

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