QCheck vs ScalaCheck
QCheck
github.comScalaCheck
scalacheck.orgSide by side
| Figure | QCheck | ScalaCheck |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Property-Based Testing Tools | 7.9 (#9) | 8.0 (#8) |
| Documentation | The project documentation site lists documentation for five opam packages, with qcheck-core, qcheck, qcheck-alcotest, and qcheck-ounit at version 0.91 and ppx_deriving_qcheck at 0.9. | The site links to a continuously developed user guide and API documentation for the latest release. |
| Installation | QCheck can be installed through opam, and the README recommends qcheck-core for a minimal dependency set. | The site recommends adding org.scalacheck %% scalacheck % 1.19.0 % test as an sbt dependency. |
| Integrations | The project provides integration layers for OUnit and Alcotest, and the README describes using QCheck with Rely through an npm package. | The site says ScalaCheck works with sbt and is integrated with ScalaTest, specs2 and LambdaTest. |
| License | The repository identifies its license as BSD-2-Clause and says the code is released under the BSD license. | The project build identifies its license as BSD-3-Clause. |
| Maintainer | The project page says it is maintained by c-cube, whose GitHub profile identifies Simon Cruanes. | The project build lists Rickard Nilsson as a developer. |
| Purpose | QCheck is a QuickCheck-inspired property-based testing library for OCaml. | ScalaCheck is a Scala library for automated property-based testing of Scala or Java programs. |
Plans
In their own words
QCheck
QCheck is a property-based testing library for OCaml, inspired by QuickCheck. Rather than relying only on hand-picked examples, it provides combinators to generate values such as lists, arrays, tuples, recursive types, and algebraic types for checking properties. When a check fails, generators can be paired with printers and shrinkers to show and reduce counterexamples. QCheck2 builds shrinking into its generators, though the project describes that API as less battle-tested than QCheck. The package family includes qcheck-core, qcheck-ounit, qcheck-alcotest, qcheck, and ppx_deriving_qcheck; the last can derive generators from type declarations. Runner options include QCheck_base_runner in qcheck-core and QCheck_runner with OUnit compatibility in qcheck, with integration layers for OUnit and Alcotest. The project also points to qcheck-stm for sequential and parallel model-based tests and qcheck-lin for sequential consistency testing. Installation is available through opam, and the source can be built with make. The minimal qcheck-core package depends only on unix and dune. QCheck is free and licensed under BSD-2-Clause.
ScalaCheck
ScalaCheck is a free Scala library for automated property-based testing of Scala and Java programs. It checks defined properties against randomized input parameters and reports the arguments that produce a failure. The library supports parameterized cases and parallel execution, and can run on its own with a built-in test runner. For sbt projects, the site shows how to add it as a test dependency; it is also integrated with ScalaTest, specs2 and LambdaTest. ScalaCheck has no external dependencies beyond the Scala runtime. Build artifacts are published in the Central Repository, with an sbt dependency declaration available from the download page. Documentation includes a user guide and API reference. The site lists version 1.19.0, released September 6, 2025. The project identifies the BSD-3-Clause license and lists a security policy. Its build defines JVM, Scala.js and Scala Native platforms, and its README says the Gradle plugin supports Scala.js and Scala Native. The site names the Scala compiler and Akka among projects that use it.