Starlight is a documentation theme built on top of Astro that provides a full-featured, accessible, and performant documentation website framework with minimal configuration. It solves the challenge of building documentation sites that are fast by default by leveraging Astro's zero-JavaScript architecture — shipping static HTML with no client-side JavaScript for content pages while islands hydrate only where interactivity is needed. Writers focus on Markdown or MDX while Starlight handles layout, navigation, theming, and search automatically.
Its feature set includes light and dark mode with automatic theming, full-text search powered by Pagefind with no external service required, versioned documentation with branch-based navigation, internationalization with per-language content trees, autogenerated sidebars from file structure, table-of-contents components, reading time hints, and extensive customization via Astro components or CSS variables. Starlight also exposes slots and component overrides, so teams can drop in custom headers, footers, or landing-page hero sections without forking the theme.
Starlight is ideal for open-source maintainers, product teams, and technical writers who want a polished documentation site without the overhead of configuring Docusaurus, VitePress, or a custom Next.js setup. The project is maintained by the Astro core team, ships frequent releases, and has become a common choice for library docs and developer handbooks across the JavaScript ecosystem, often compared to VitePress and Docusaurus as the 'batteries included Astro' option.
