JUnit 5 vs Testing Library

Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.

JUnit 5Testing Library

Entry price

Free and open source

Open source

Free and open source

Open source

What drives the bill

The metric that actually scales your invoice.

Free and open source. You pay in engineering time and CI minutes.

Free tier

Everything, self-hosted

Open source

EPL-2.0

MIT

Self-hostable

No-code authoring

Languages

JavaKotlin

JavaScriptTypeScript

Platforms

WebAPI

Web

Fits teams

Solo / side projectStartupScale-up / mid-marketEnterprise

Adoption

Category standard

JUnit Team · since 2017

Category standard

OSS community · since 2018

Strengths

Universal support across IDEs, build tools and CI in the Java ecosystem.
The extension model replaced JUnit 4's runners and rules with something composable.
Pairs cleanly with Mockito, AssertJ, Spring Test and Testcontainers.

Tests survive refactors because they assert on user-visible output, not internals.
Accessible-role queries push teams towards accessible markup as a side effect.
One idiom across every major front-end framework.

Limitations

Java verbosity persists — expect more lines per test than in Python or JavaScript.
Parallel execution is opt-in and still occasionally surprising.
Mixed JUnit 4 and 5 codebases need the vintage engine and stay confusing for years.

Deliberately makes implementation-detail testing hard, which frustrates teams used to shallow rendering.
Async utilities and act() warnings are a common source of confusion.
Needs a runner and a DOM environment alongside it.

Best for

Every Java and Kotlin project on the JVM.

Any front-end team writing component tests, regardless of framework.

Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.