Next.js: The Ultimate Guide to Server-Side Rendering

Next.js extends React with file-based routing, SSR, SSG, and API routes. Understanding when each rendering mode applies is essential for performance and SEO.

Rendering Modes

Static Generation (SSG) pre-renders at build time-ideal for marketing pages and blogs. Server-Side Rendering (SSR) renders on each request-best for personalized or frequently changing data. Client-Side Rendering (CSR) hydrates in the browser for highly interactive dashboards.

getServerSideProps Example

export async function getServerSideProps({ params }) {
  const res = await fetch(`https://api.example.com/posts/${params.id}`);
  const post = await res.json();
  return { props: { post } };
}

App Router (Preview)

Next.js 13+ introduces the App Router with React Server Components. Pages Router patterns remain widely used-know both as you maintain legacy and greenfield apps.

Deployment

Deploy to Vercel with zero config, or self-host with next start behind a reverse proxy. Use ISR (Incremental Static Regeneration) for content that changes occasionally without full rebuilds.

Conclusion

Next.js is the default React framework for full stack teams who need SEO, fast first paint, and API colocation. Pick SSG when you can, SSR when you must, and measure with Lighthouse.