Astro Web Framework

Astro is a free and open-source web framework for building fast, content-driven websites that ship zero JavaScript by default. Created by Fred K. Schott and the Astro Team in 2021, Astro is designed for blogs, marketing sites, portfolios, documentation sites, and e-commerce stores where content is the primary focus and page load speed is critical. Key features: Islands Architecture: Astro's core innovation. Instead of shipping a JavaScript-heavy single-page application, Astro renders pages to static HTML on the server and only hydrates (adds interactivity to) individual components called 'islands'. This dramatically reduces the amount of JavaScript sent to the browser, resulting in faster page loads and better Core Web Vitals. Component islands can be configured with client directives (client:load, client:idle, client:visible, client:media, client:only) to control when and how they hydrate. Zero JS by default: Astro components render to static HTML with no client-side JavaScript unless explicitly opted in. UI framework agnostic: import and use components from React, Vue, Svelte, Solid, Preact, Lit, and others in the same project. Components from different frameworks can coexist on the same page, each as a separate island. File-based routing: pages are defined in the src/pages directory, with the file path becoming the URL path. Dynamic routes using [slug] parameters. Content Collections: type-safe content management for Markdown, MDX, and data files. Collections provide schema validation via Zod, frontmatter type-checking, and content querying. Server-side rendering (SSR) and static site generation (SSG): Astro supports both output modes, switchable via configuration. SSR adapters for Node.js, Cloudflare, Vercel, Netlify, and Deno. Vite-powered: uses Vite for development server, HMR, and bundling. TypeScript first-class support. Integrations ecosystem. MIT.