---
title: 'Storybook 6.3 - June 2021'
prerelease: false
---

## [Optimized for UI development](https://storybook.js.org/blog/storybook-6-3/)

SB6.3 adds new UI development and testing features, while evolving with the JS ecosystem:

- 📐 Layout debugging with Measure and Outline addons
- 🔌 Reuse your stories in unit tests: Jest & Cypress
- 🚀 Frameworks: Angular 12 Ivy, Lit2 web components
- 🛠 Builders: Webpack5 stable, Vite community
- 📦 Packaging: Modern ESM

---

6.3 contains hundreds more fixes, features, and tweaks. Browse the [changelogs](https://github.com/storybookjs/storybook/blob/next/CHANGELOG.md) matching `6.3.0-alpha.*`, `6.3.0-beta.*`, and `6.3.0-rc.*` for the full list of changes. See [Storybook 6 migration guide](https://storybook.js.org/blog/storybook-6-migration-guide/) to upgrade from `5.x` or [MIGRATION.md](https://github.com/storybookjs/storybook/blob/next/MIGRATION.md) for detailed migration instructions.
