Key Takeaways
- Hydration is the performance cost of SSR: the browser must re-process the entire page to make it interactive.
- Hydration errors (server/client HTML mismatch) are the most common SSR debugging challenge.
- Partial hydration (Astro islands) eliminates unnecessary hydration by only adding JavaScript to interactive components.
Hydration Strategies Compared
| Strategy | Framework | Trade-off |
|---|---|---|
| Full hydration | Next.js, Remix | All components hydrated, largest JS bundle |
| Selective hydration | React 18+ | Prioritizes interactive components, progressive |
| Partial hydration (islands) | Astro | Only interactive components hydrated, minimal JS |
| Resumability | Qwik | No hydration needed, serialized state resumes instantly |
Astro's island architecture is the most efficient for content-heavy sites: a blog page with one interactive comment form hydrates only the comment component, shipping zero JS for the rest of the page.
Frequently Asked Questions
Related Services
Related Terms
React
A JavaScript library for building user interfaces using reusable components and a virtual DOM.
SSR
Server-Side Rendering. Generating HTML on the server for each request, improving SEO and initial load time.
Server Component
A React component that renders exclusively on the server, sending only HTML to the client without any client-side JavaScript.
Need Help With Implementation?
Our team specializes in implementing the solutions described in this glossary.
Get in Touch