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Head-to-head · Property-Based Testing Tools

fast-check vs ScalaCheck

  • Updated Nov 2026
  • Both researched from official sources
  • 4 checks side by side
Higher score fast-check #1 in Property-Based Testing Tools 9.4/10 Open source Free plan✓ 3 of 3 features Visit fast-check
ScalaCheck #8 in Property-Based Testing Tools 8.6/10 Free plan Free plan✓ 0 of 3 features Visit ScalaCheck

fast-check leads on 0 checks, ScalaCheck on 0, and 4 are even. Who comes out ahead on the 4 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scorefast-check · 9.4/10
  • Free planboth
  • Most featuresfast-check · 3 of 3

fast-check scores higher on our rubric for property-based testing tools: 9.4 against 8.6 out of 10; our editors rank them #1 and #8.

fast-check is the better fit for javaScript and TypeScript teams. ScalaCheck is the better fit for scala teams needing broad integration.

  • fast-check fits best

    JavaScript and TypeScript teams

  • ScalaCheck fits best

    Scala teams needing broad integration

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Side by side

Feature fast-check 9.4/10 Visit ↗ ScalaCheck 8.6/10 Visit ↗
At a glance
Editor score 9.4 8.6
Ranking #1 in Property-Based Testing Tools #8 in Property-Based Testing Tools
Best for JavaScript and TypeScript teams Scala teams needing broad integration
Pricing model Free Free
Starting price Open source Free plan
Free plan ✓ ✓
Free trial — —
Deployment Self-hosted Self-hosted
Support Docs, Community Community, Docs
Integrations 7 integrations 6 integrations
Built for Solo, Small business, Mid-market, Enterprise Solo, Small business, Mid-market, Enterprise
Features fast-check 3/3 · ScalaCheck 0/3
Failing-case shrinking ✓ (best) Not checked yet
Stateful testing ✓ (best) Not checked yet
Reproducible failures ✓ (best) Not checked yet
Specs
Supported languages JavaScript, TypeScript Scala, Java
Test runner support Jest, Mocha, Vitest, Ava, Bun, Deno, Node.js test runner Not checked yet
Cases per run Not checked yet Not checked yet
Our review
Pros
  • Shrinks failures and supports deterministic replay with seeds and paths
  • Supports stateful, asynchronous, fuzzing, and scheduler-based testing
  • Integrates with Jest, Mocha, Vitest, Ava, Bun, Deno, and Node.js
  • Automatic generation, shrinking, and minimization of failing cases
  • Stateful command testing and configurable parallel execution
  • Integrates with sbt, ScalaTest, specs2, Gradle, Scala.js, and Scala Native
Cons
  • Its scope is limited to JavaScript and TypeScript
  • Advanced stateful and scheduler workflows require thoughtful test design
  • It does not provide AI-assisted testing features
  • Requires developers to define properties and test data generators
  • Its supported language focus is Scala and Java
  • Self-hosted distribution puts setup and execution in the development workflow
Our verdict

fast-check is an open-source property-based testing library for JavaScript and TypeScript. It generates inputs, runs properties repeatedly, and reduces failing inputs to smaller cases that are easier to investigate. The library suits teams…

Read the review →

ScalaCheck is an open-source property-based testing library for Scala and Java programs. Developers define properties with universally quantified assertions, and the library generates test data, evaluates those properties repeatedly, and…

Read the review →
  1. fast-checkProperty-Based Testing Tools 9.4Open source
  2. ScalaCheckProperty-Based Testing Tools 8.6Free plan

Strengths and trade-offs

  • fast-check — where it wins

    • Shrinks failures and supports deterministic replay with seeds and paths
    • Supports stateful, asynchronous, fuzzing, and scheduler-based testing
    • Integrates with Jest, Mocha, Vitest, Ava, Bun, Deno, and Node.js

    Where it doesn't

    • Its scope is limited to JavaScript and TypeScript
    • Advanced stateful and scheduler workflows require thoughtful test design
    • It does not provide AI-assisted testing features

  • ScalaCheck — where it wins

    • Automatic generation, shrinking, and minimization of failing cases
    • Stateful command testing and configurable parallel execution
    • Integrates with sbt, ScalaTest, specs2, Gradle, Scala.js, and Scala Native

    Where it doesn't

    • Requires developers to define properties and test data generators
    • Its supported language focus is Scala and Java
    • Self-hosted distribution puts setup and execution in the development workflow

fast-check vs ScalaCheck: questions

Which is better for Property-Based testing tools, fast-check or ScalaCheck?

fast-check scores higher on our rubric for property-based testing tools: 9.4 against 8.6 out of 10; our editors rank them #1 and #8.

How do fast-check and ScalaCheck compare?

All 4 checks we put side by side come out level: neither leads on any.

Do fast-check and ScalaCheck have a free plan?

fast-check: Yes. ScalaCheck: Yes.

More comparisons

All Property-Based testing tools comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Nov 2026

Last updated · How we research and update