NUnit 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.

NUnitTesting 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

MIT

Self-hostable

No-code authoring

Languages

JavaScriptTypeScript

Platforms

WebAPIDesktop

Web

Fits teams

Scale-up / mid-marketEnterprise

Solo / side projectStartupScale-up / mid-marketEnterprise

Adoption

Widely used

.NET Foundation · since 2002

Category standard

OSS community · since 2018

Strengths

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

Shared test-class instances mean state can leak between tests unless you are careful.
New Microsoft templates default to xUnit, so it is drifting from the mainstream.
Attribute-heavy style feels dated.

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

Existing .NET codebases already standardised on NUnit.

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.