pytest vs Storybook

Free and open source

Free and open source

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

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

Everything, self-hosted

Everything, self-hosted

Category standard

pytest-dev · since 2004

Category standard

Chromatic / OSS community · since 2016

• Fixtures are the best dependency-injection model in any test framework, and they compose cleanly.
• Assertion introspection produces genuinely useful failure output from a plain assert.
• Vast plugin ecosystem — pytest-xdist, pytest-cov, pytest-asyncio, pytest-django.

• 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.

• Fixture scope and ordering become genuinely hard to reason about in large suites.
• The magic that makes simple cases elegant makes complex cases opaque.
• Python only.

• 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.

Essentially every Python project.

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