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Databases · head to head

DuckDB vs Formance

DuckDB logo

DuckDB

Databases

MIT-licensed analytical SQL database that runs inside your process, with no server, no dependencies and one writer at a time.

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: DuckDB a database file accepts one read-write process at a time; other processes must open it read-only and will not see subsequent writes, so DuckDB cannot be the shared database behind several services.; 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: DuckDB covers In-process execution, Formance covers Double-entry ledger.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which DuckDB and Formance actually diverge.

Attributes where DuckDB and Formance differ
AttributeDuckDBFormance
Pricing modelopen-sourceOpen source, no licence fee
PlatformsLinux, macOS, Windows, WebAssemblyLinux, Docker, Kubernetes, Web, API
CategoryDatabasesAPIs
Founded2019Unknown

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 DuckDB

  • In-process execution
  • Vectorised columnar engine
  • Direct file querying
  • Zero dependencies
  • Larger-than-memory queries
  • MIT licence
  • Postgres-flavoured SQL
  • Extension ecosystem

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.

DuckDB

  • Transformation steps in a data pipeline that would otherwise need Spark, replaced by SQL over Parquet in a single processnot Formance
  • Analytical queries embedded in an application or a dashboard where shipping a database server alongside it is not acceptablenot Formance
  • Local exploration of files that are too large for a pandas dataframe but far too small to justify a warehousenot Formance
  • Continuous integration and testing of analytical SQL, where a real engine can run in the test process without provisioning anythingnot Formance

Formance

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

Where each one falls short

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

DuckDB

  • A database file accepts one read-write process at a time; other processes must open it read-only and will not see subsequent writes, so DuckDB cannot be the shared database behind several services.
  • There is no network protocol, authentication or user management, so exposing it to remote clients means writing and securing your own service around it.
  • It is built for scans and aggregations, not for many small transactions, so a workload of high-frequency single-row inserts and updates performs badly compared with SQLite or Postgres.
  • Storage files are backwards compatible but not forwards compatible, so a file written by a newer version cannot be read by an older one and every consumer of a shared file must be upgraded together.
  • Query memory settings matter: some operations still need to hold significant state, so an under-configured memory limit turns a large join or a high-cardinality aggregation into a spill-heavy query or an out-of-memory failure rather than a slow success.

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

DuckDB

Free

No published plan breakdown. See the DuckDB review.

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 DuckDB if

  • You need in-process execution.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, WebAssembly.
  • You also want vectorised columnar engine.
DuckDB 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 DuckDB or Formance better?
Neither clearly leads. DuckDB 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, DuckDB or Formance?
DuckDB starts at Free and Formance at Free.
Does DuckDB or Formance run on more platforms?
DuckDB runs on Linux, macOS, Windows, WebAssembly. Formance runs on Linux, Docker, Kubernetes, Web, API.
Can I use DuckDB for free?
Both have a free tier, so you can try either at no cost before committing.
What is DuckDB best used for?
DuckDB is most often used for transformation steps in a data pipeline that would otherwise need spark, replaced by sql over parquet in a single process, analytical queries embedded in an application or a dashboard where shipping a database server alongside it is not acceptable, local exploration of files that are too large for a pandas dataframe but far too small to justify a warehouse, continuous integration and testing of analytical sql, where a real engine can run in the test process without provisioning anything. Of those, transformation steps in a data pipeline that would otherwise need spark, replaced by sql over parquet in a single process and analytical queries embedded in an application or a dashboard where shipping a database server alongside it is not acceptable are not what Formance is typically brought in for.
What can DuckDB do that Formance cannot?
DuckDB covers In-process execution, Vectorised columnar engine, Direct file querying, Zero dependencies. Formance covers Double-entry ledger, Numscript transaction DSL, Multi-currency, Payments connectivity.

Answered from the vendors’ own pages

DuckDB: Can multiple applications share one DuckDB database?

Not for writing. One process holds the database read-write; others may attach read-only and will not see later writes. Shared multi-writer access needs a different database or a table format with a catalogue.

Formance: Is Formance really open source?

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

DuckDB: Is it a replacement for a data warehouse?

For single-node analytical workloads up to a few hundred gigabytes it very often is. It is not a replacement when many concurrent users need a shared, governed, always-on service.

Formance: Does Formance move money?

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

DuckDB: Do I have to load data into it?

No. It queries Parquet, CSV, JSON and Arrow in place, including on object storage. Its own storage format is optional and mainly useful when you want indexes, constraints and faster repeated access.

Formance: What does the enterprise version cost?

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

DuckDB: What is MotherDuck's relationship to it?

MotherDuck is a separate company offering a managed and hybrid service built on the DuckDB engine. DuckDB itself remains MIT-licensed and independent of it, with the IP held by the DuckDB Foundation.

Formance: Do I have to use Numscript?

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

DuckDB: Is it suitable for OLTP?

No. It is designed for analytical scans. For transactional workloads with frequent small writes, SQLite or Postgres is the right tool.

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