Islands

ELI5 — The Vibe Check

Islands architecture is shipping a static HTML page with small 'islands' of interactive JavaScript. Everything that isn't a button or form stays as pure HTML — no JS, no hydration. Astro made this mainstream. Page weight drops dramatically.

Real Talk

Islands architecture is a frontend rendering pattern where the bulk of a page is static HTML with isolated interactive 'islands' hydrated independently. Pioneered by Jason Miller and popularized by Astro, Fresh, and Marko. Each island hydrates separately, reducing time-to-interactive and JS payload compared to full-page hydration. Partial hydration variants include lazy and interaction-triggered hydration.

When You'll Hear This

"Astro's islands cut our JS bundle 90%." / "Don't ship a full React tree — use islands."