Islands Architecture
Web applications have grown more capable, but users still expect pages to load quickly. Traditional single-page applications often trade first-load performance for rich interaction.
Astro’s islands architecture offers a different default: render mostly static HTML, then hydrate only the interactive pieces.
Core Concepts
- Pages are static HTML by default.
- Interactive components are explicitly marked.
- Each island loads independently.
Performance Benefits
This approach can improve first contentful paint, reduce JavaScript payloads, and preserve SEO-friendly HTML. It also forces a useful question: does this part of the page really need to run in the browser?
Where It Fits
Astro is especially strong for blogs, documentation, marketing pages, and content-heavy sites where interactivity supports the page rather than defining the whole product.