Mocha 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

Widely used

OpenJS Foundation · since 2011

Category standard

Chromatic / OSS community · since 2016

• Small, stable and predictable — it does one job and has done it the same way for years.
• Pick your own assertions, mocks and coverage rather than accepting a bundle.
• Excellent async and reporter support.

• 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.

• No built-in mocking, snapshots, coverage or parallel-by-default execution.
• Assembling and documenting the stack is work every new project repeats.
• Fewer new projects adopt it; momentum sits with Vitest and Jest.

• 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.

Node.js services where you want explicit control over every part of the test stack.

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