Mastering Rendering in Next.js 15: A Deep Dive into SSR, RSC, and More! 🚀

Next.js 15 brings several advancements in rendering techniques, refining performance, flexibility, and developer experience. Understanding the different rendering methods available is crucial for optimizing application speed, scalability, and SEO. In this post, we will explore the various rendering strategies in Next.js 15 and their use cases.

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🚀 Rendering Methods in Next.js 15

1. Server-Side Rendering (SSR)

Server-Side Rendering generates the HTML for a page at request time on the server. This is useful for dynamic content that needs to be up-to-date with each request.

Example:

export async function getServerSideProps() {
  const res = await fetch('https://api.example.com/data');
  const data = await res.json();

  return {
    props: { data },
  };
}

export default function Page({ data }) {
  return <div>{data.content}</div>;
}

✅ Best for pages that require fresh data on every request.

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2. Static Site Generation (SSG)

SSG pre-builds the HTML at compile time, making it lightning fast for end users. This is great for static pages like blogs and marketing sites.

Example:

export async function getStaticProps() {
  const res = await fetch('https://api.example.com/data');
  const data = await res.json();

  return {
    props: { data },
    revalidate: 10, // Incremental Static Regeneration (ISR)
  };
}

export default function Page({ data }) {
  return <div>{data.content}</div>;
}

✅ Ideal for content that doesn’t change frequently but still needs periodic updates.

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3. React Server Components (RSC) (NEW!)

Next.js 15 further enhances React Server Components, which allow developers to fetch and process data on the server while keeping interactivity on the client side. RSC reduces JavaScript bundle size and improves page load times.

Example:

export default async function Page() {
  const data = await fetch('https://api.example.com/data').then(res => res.json());

  return (
    <div>
      <h1>{data.title}</h1>
      <p>{data.content}</p>
    </div>
  );
}

✅ Improves performance by reducing client-side JavaScript execution.

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4. Client-Side Rendering (CSR)

CSR renders content in the browser using JavaScript, often with useEffect to fetch data after the page loads.

Example:

import { useEffect, useState } from 'react';

export default function Page() {
  const [data, setData] = useState(null);

  useEffect(() => {
    fetch('https://api.example.com/data')
      .then(res => res.json())
      .then(setData);
  }, []);

  if (!data) return <p>Loading...</p>;

  return <div>{data.content}</div>;
}

✅ Best for highly interactive, dynamic pages where SEO is not a priority.

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5. Incremental Static Regeneration (ISR)

ISR is a hybrid approach that allows static pages to be updated without rebuilding the entire site.

Example:

export async function getStaticProps() {
  const res = await fetch('https://api.example.com/data');
  const data = await res.json();

  return {
    props: { data },
    revalidate: 60, // Rebuilds page every 60 seconds
  };
}

✅ Ideal for large-scale applications that need some content freshness without SSR overhead.

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🔥 What’s New in Next.js 15?

• Improved support for React Server Components for faster rendering.
• Better caching and streaming capabilities.
• Optimized hydration for improved interactivity.
• Seamless integration with Edge and Middleware.

🎯 Choosing the Right Rendering Strategy

Feature	SSR	SSG	RSC	CSR	ISR
SEO Friendly	✅	✅	✅	❌	✅
Performance	⚡	🚀	🔥	⚡	🚀
Dynamic Data	✅	❌	✅	✅	✅
Client Interactivity	⚡	⚡	✅	✅	⚡

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🚀 Conclusion

Next.js 15 continues to push the boundaries of web performance with improved rendering strategies. Understanding SSR, SSG, RSC, CSR, and ISR helps developers choose the best method for their projects. By leveraging the right approach, you can build faster, more scalable, and SEO-friendly web applications.

What rendering strategy do you use the most? Let’s discuss in the comments!