Astro
A free, open-source web framework for fast, content-focused websites.
Astro is an open-source web framework, MIT-licensed, for building content-focused websites such as marketing sites, blogs and documentation. Pages are rendered to HTML by default, and JavaScript loads only for the interactive parts, which Astro calls islands.
It works with React, Vue, Svelte or plain HTML, pulls content from Markdown or any headless CMS, and deploys to almost any host. The company behind it joined Cloudflare in January 2026, and Astro stays open source and platform-agnostic.
Key characteristics
- Ships very little JavaScript by default.
- Supports several UI libraries as interactive islands.
- Content from Markdown, MDX or a headless CMS.
- Built and edited by developers, not visually.
Example
A developer tools company builds its docs and marketing site in Astro from Markdown files in its repository, and hosts it on a free static plan.
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Frequently asked questions
Is Astro free?
Yes. Astro is open source under the MIT license; you pay only for hosting.
Is Astro a website builder?
No. It is a framework developers write code in. Visual builders such as Framer and Webflow let non-developers edit pages directly.
Related terms