Is DuckDB or HAProxy better?

Neither clearly leads. DuckDB starts at Free and HAProxy at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.

Which is cheaper, DuckDB or HAProxy?

DuckDB starts at Free and HAProxy at Free.

Does DuckDB or HAProxy run on more platforms?

DuckDB runs on Linux, macOS, Windows, WebAssembly. HAProxy runs on Linux, Docker, Kubernetes, Self-hosted.

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 HAProxy is typically brought in for.

What can DuckDB do that HAProxy cannot?

DuckDB covers In-process execution, Vectorised columnar engine, Direct file querying, Zero dependencies. HAProxy covers High throughput, Layer 4 and 7, Health checking, Rate limiting and ACLs.

Databases · head to head

DuckDB vs HAProxy

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 review Website

HAProxy

Cloud

High-performance TCP and HTTP load balancer

From: Free
Rated: -

Full review Website

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.; HAProxy configuration syntax is dense and unforgiving, with a steep initial learning curve
They diverge on capability: DuckDB covers In-process execution, HAProxy covers High throughput.
Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which DuckDB and HAProxy actually diverge.

Attributes where DuckDB and HAProxy differ
Attribute	DuckDB	HAProxy
Pricing model	open-source	Open source, no licence fee
Platforms	Linux, macOS, Windows, WebAssembly	Linux, Docker, Kubernetes, Self-hosted
Category	Databases	Cloud
Founded	2019	Unknown

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 HAProxy

High throughput
Layer 4 and 7
Health checking
Rate limiting and ACLs

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 HAProxy
Analytical queries embedded in an application or a dashboard where shipping a database server alongside it is not acceptablenot HAProxy
Local exploration of files that are too large for a pandas dataframe but far too small to justify a warehousenot HAProxy
Continuous integration and testing of analytical SQL, where a real engine can run in the test process without provisioning anythingnot HAProxy

HAProxy

Load balancing at traffic levels where proxy efficiency shows up in the hardware billnot DuckDB
Precise traffic control — rate limits, sticky sessions, complex routing rulesnot DuckDB
TCP load balancing for databases and non-HTTP servicesnot 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.

HAProxy

Configuration syntax is dense and unforgiving, with a steep initial learning curve
No automatic certificate management, unlike newer servers that treat it as default behaviour
The built-in stats page is basic, so real observability needs exporters and dashboards
A dedicated load balancer is more machinery than small deployments need

Pricing, plan by plan

DuckDB

Free

No published plan breakdown. See the DuckDB review.

HAProxy

Free

HAProxyFree
- Full functionality
- No usage limits
- Community support

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 HAProxy if

You need high throughput.
You want to start without paying.
You work on Linux, Docker, Kubernetes, Self-hosted.
You also want layer 4 and 7.

HAProxy review

Questions people ask

Is DuckDB or HAProxy better?: Neither clearly leads. DuckDB starts at Free and HAProxy at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, DuckDB or HAProxy?: DuckDB starts at Free and HAProxy at Free.
Does DuckDB or HAProxy run on more platforms?: DuckDB runs on Linux, macOS, Windows, WebAssembly. HAProxy runs on Linux, Docker, Kubernetes, Self-hosted.
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 HAProxy is typically brought in for.
What can DuckDB do that HAProxy cannot?: DuckDB covers In-process execution, Vectorised columnar engine, Direct file querying, Zero dependencies. HAProxy covers High throughput, Layer 4 and 7, Health checking, Rate limiting and ACLs.

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.

HAProxy: Is HAProxy free?

Yes, the community version is open source. HAProxy Technologies sells HAProxy Enterprise separately.

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.

HAProxy: HAProxy or Nginx?

HAProxy is a specialist load balancer with deeper balancing and health-check features. Nginx also serves static content and is more approachable, which is why it is more common as a general web server.

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.

HAProxy: Does HAProxy handle TLS certificates automatically?

No. Certificate issuance and renewal are external, unlike Caddy where it is automatic.

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.

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.

DuckDB vs HAProxy

DuckDB

HAProxy

The short version

Where they differ

What each one covers

Only in DuckDB

Only in HAProxy

What people use each for

DuckDB

HAProxy

Where each one falls short

DuckDB

HAProxy

Pricing, plan by plan

DuckDB

HAProxy

Which should you pick?

Choose DuckDB if

Choose HAProxy if

Questions people ask

Answered from the vendors’ own pages

Related pages

More on DuckDB

More on HAProxy

Keep looking

Other head to heads