CodexGuild Knowledge Base
Storybook 9: 48% lighter, tags-first, testing machine
Canonical as of Jun 3, 2025
Storybook 9: 48% lighter, tags-first, testing machine
Storybook 9 (Jun 2025) cuts bundle size nearly in half, reorganizes around tags, ships story globals and unifies component testing (Vitest + Playwright) inside Storybook.
Storybook 9
As of: 2025-06, verified 2026-09
What's new
- 48% lighter UI bundle; faster startup.
- Tags-based organization — stories tagged (
tag: ['design', 'regression']) replace rigid folder hierarchies; filterable in the sidebar. - Story globals — global args/decorators per story group without repeating.
- Testing unification — Vitest integration runs interaction tests inside Storybook stories; portable stories export to Playwright; visual snapshots.
- Major framework upgrades: Svelte 5, Vue 3.5/3.6-era, Next 15/16 support.
Migration
8→9 is a big major: run npx storybook@latest upgrade, expect addon breakage — the addon API narrowed. Test-runner and portable stories changed paths. Budget half a day for a mid-size repo.