1. What is Islands Architecture?

Islands Architecture is a method of achieving Partial Hydration (hydrate parts of page independently), by creating separate islands of interactivity alongside static HTML

2. How does Islands Architecture work?

How does islands architecture work
  1. First the client sends a get request to the server
  2. the server executes all app logic
  3. in order to render the complete HTML page
  4. which it sends back to the client
  5. the client renders the HTML page
  6. and sends a request for each island
  7. once it receives an island
  8. the client executes all island logic again
  9. so as to hydrate it

3. What are the Pros and Cons of Islands Architecture?


  • great performance
  • great SEO
  • good accessibility
  • defer loading and hydration of unimportant parts of the page


  • limited number of tools offering Islands Architecture
  • not suitable for highly interactive apps
  • page change causes refresh
  • execute all app logic twice
    • once on the server and once on the client

4. When should you use Islands Architecture?

  • when your site contains both static and interactive parts
  • when you want fast First Paint (FP), First Contentful Paint (FCP) and Time To Interactive (TTI)
  • when you want to bring your own framework (use Astro)

Perfect for content-rich websites like blogs, marketing sites, documentation sites and some e-commerce sites

see also Progressive Hydration, React Server Components and Resumability


Islands Architecture
The islands architecture encourages small, focused chunks of interactivity within server-rendered web pages
Why Astro?
Astro is an all-in-one web framework for building fast, content-focused websites. Learn more.
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