QuickCheck is a free Haskell library for testing program properties against randomly generated cases. Developers express specifications with QuickCheck combinators and can use combinators to define test-data generators and examine the distribution of generated data. The Test.QuickCheck.Monadic module provides monadic property testing; the library also supports stateful testing, shrinking failing cases and reproducible failures. The package README describes adding QuickCheck to project dependencies for use in tests or a REPL. A companion package, quickcheck-instances, supplies instances for types in Haskell Platform packages, with additional dependencies. QuickCheck is licensed under BSD-3-Clause and lists dependencies including base, containers, random, splitmix, template-haskell and transformers. Hackage reports testing with GHC versions from 8.10 up to but not including 9.15, as well as Hugs. A make-hugs script creates a Hugs-compatible version and may be useful with other non-GHC implementations. Hackage lists QuickCheck-2.18.0.0 as a downloadable Cabal source package.

Who it is for

QuickCheck suits Haskell developers who want to check program properties using generated inputs. Its generator and distribution combinators can support testing that requires custom test data.

What is good

Specifications and generators use Haskell combinators
Supports shrinking failing cases
Supports stateful and monadic property testing
Licensed under BSD-3-Clause

What to know first

Requires Haskell project dependencies
Companion package adds dependencies
Reported GHC testing is below version 9.15

Verdict

QuickCheck provides property-testing tools for Haskell, including generators, shrinking and stateful tests. Review its dependency list and reported compiler compatibility before adding it to a project.

QuickCheck plans and pricing

All plans

QuickCheck Free Haskell library for random testing of program properties hackage.haskell.org · 2 Oct 2026

Compared on property-based testing tools

Free plan: Yes
Supported languages: Haskell
Test runner support: Test.SmallCheck.Drivers
Failing-case shrinking: Yes
Stateful testing: Yes
Reproducible failures: Yes

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The record

Purpose

QuickCheck is a Haskell library for random testing of program properties by checking specifications against randomly generated cases.

Property specifications

Program specifications are expressed in Haskell using QuickCheck combinators.

Generators

QuickCheck provides combinators for defining test data generators.

Data distribution

QuickCheck provides combinators to observe the distribution of test data.

Monadic testing

The monadic property testing library is provided in the Test.QuickCheck.Monadic module.

Companion package

The quickcheck-instances companion package provides instances for types in Haskell Platform packages, with additional dependencies.

Use

The package README says to add QuickCheck to package dependencies to use it in tests or a REPL.

Hugs compatibility

The make-hugs script creates a Hugs-compatible version and may be useful for other non-GHC implementations.

License

The package is licensed under BSD-3-Clause.

Dependencies

The package lists dependencies including base, containers, random, splitmix, template-haskell, and transformers.

Compiler compatibility

Hackage reports the package tested with GHC versions at least 8.10 and below 9.15, and Hugs.

Download

Hackage lists QuickCheck-2.18.0.0 as a downloadable Cabal source package.

Price from

Free