Storybook vs unittest

Free and open source

Free and open source

Storybook itself is free. Chromatic, the hosted visual-review service from the same team, is a separate paid product.

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

Everything, self-hosted

Everything, self-hosted

Category standard

Chromatic / OSS community · since 2016

Widely used

Python Software Foundation · since 2001

• One artefact serves as documentation, visual baseline and interaction test.
• Design-system teams get a shared reference that designers can actually open.
• Rich addon ecosystem for accessibility, viewport and state manipulation.

• In the standard library — nothing to install or vet.
• unittest.mock is excellent and used almost universally in Python.
• Familiar to anyone coming from JUnit or NUnit.

• Meaningful configuration and maintenance overhead; a neglected Storybook rots fast.
• Build times on large component libraries get long.
• Stories drift from production usage unless discipline is enforced.

• Verbose compared to pytest for the same coverage.
• No parametrisation or fixture composition worth the name.
• Most teams run unittest tests through pytest anyway.

Teams maintaining a design system or a large shared component library.

Standard-library-only environments and codebases that already use it.