6 Ways On How To Optimize Next.js for Speed & Scalability

When building a scalable SaaS with Next.js, performance isn’t just a luxury—it’s a necessity. A fast, well-optimized platform means better user experience, improved SEO rankings, and lower server costs. But as your SaaS grows, so do the challenges: slow-loading pages, bloated JavaScript bundles, inefficient data fetching—sound familiar?

If you’ve already laid the foundation for scalability in Next.js, as we discussed in “Building Scalable SaaS with Next.js: 10 Key Strategies to Grow Your Platform”, the next step is fine-tuning your app for speed and performance. This guide dives into the best practices to optimize Next.js, from smart image handling to reducing JavaScript overhead and leveraging edge functions for lightning-fast response times.

Let’s get into the 6 ways to make your Next.js app faster and more scalable

1. Optimize Image Loading with Next.js Image Component

Images are often the largest assets on a webpage, and if not optimized properly, they can slow down your site. Next.js provides a built-in <Image> component that automatically optimizes images, reducing load times and improving performance.

Use the Next.js <Image> Component Instead of <img>

Unlike a regular <img> tag, the Next.js <Image> component serves images in modern formats (WebP, AVIF), compresses them efficiently, and adapts their size based on the user’s device. Below is an example code snippet demonstrating how the <Image> component is used instead of the conventional <img> tag:

import Image from 'next/image';

export default function OptimizedImage() {
  return (
    <Image 
      src="/images/PlanstackerBanner.jpg" 
      alt="Optimized Image example" 
      width={800} 
      height={500} 
    />
  );
}

Enable Lazy Loading and Set Priority for Critical Images

Next.js lazy-loads images by default, but for hero sections or above-the-fold images, set priority={true} to load them immediately.

<Image 
  src="/images/PlanStackerBanner.jpg" 
  alt="The Banner Of PlanStacker" 
  width={1200} 
  height={600} 
  priority 
/>

Ensure Layout Stability with Proper Sizing

To prevent layout shifts, always define width and height or use the fill property for fluid layouts.

<div style={{ position: 'relative', width: '100%', height: '400px' }}>
  <Image 
    src="/images/background.jpg" 
    alt="Background Image Of PlanStacker.com" 
    fill
    style={{ objectFit: 'cover' }} 
  />
</div>

Optimize Remote Images from External Sources

If using images from a CMS or API, configure next.config.js to allow optimization:

module.exports = {
  images: {
    domains: ['cloudinary.com'],
  },
};

Then, use it like this:

<Image 
  src="https://res.cloudinary.com/xxxx/images/photo.jpg" 
  alt="Remote Image" 
  width={800} 
  height={500} 
/>

By leveraging Next.js image optimization features, you can significantly improve load times and enhance user experience while keeping your application scalable.

2. Enable Automatic Static Optimization

Next.js is designed to optimize performance by pre-rendering pages whenever possible. By using Static Site Generation (SSG) and Incremental Static Regeneration (ISR), you can significantly improve load times and scalability while keeping your application dynamic when needed.

Use Static Site Generation (SSG) Wherever Possible

SSG pre-renders pages at build time, serving static HTML files for faster delivery and improved SEO. This is ideal for content that doesn’t change often, such as blog posts, product pages, or marketing pages.

import { GetStaticProps } from 'next';

type BlogProps = {
  title: string;
  content: string;
};

export default function BlogPost({ title, content }: BlogProps) {
  return (
    <article>
      <h1>{title}</h1>
      <p>{content}</p>
    </article>
  );
}

export const getStaticProps: GetStaticProps = async () => {
  const blogData = await fetch('https://blog.planstacker.com/blog/1').then(res => res.json());

  return {
    props: {
      title: blogData.title,
      content: blogData.content,
    },
    revalidate: 60, // Revalidate every 60 seconds if ISR is enabled
  };
};

The above code uses getStaticProps, a method of SSG that allows the page to be pre-built at deployment, enabling it to load almost instantly without backend requests.

Ensure Components Are Server-Side Rendered (SSR) Only When Needed

Server-Side Rendering (SSR) should be used when real-time, per-request data is needed (e.g., user-specific dashboards, authentication-based content). Avoid SSR for static content since it increases response time.

import { GetServerSideProps } from 'next';

type UserProps = {
  name: string;
};

export default function UserPage({ name }: UserProps) {
  return <h1>Welcome, {name}!</h1>;
}

export const getServerSideProps: GetServerSideProps = async (context) => {
  const user = await fetch(`https://api.planstacker.com/user/${context.params?.id}`).then(res => res.json());

  return {
    props: {
      name: user.name,
    },
  };
};

Note: Use SSR only when necessary, such as for user-specific content or frequently changing data.

Use Incremental Static Regeneration (ISR) for Frequently Updated Pages

ISR allows Next.js to update static pages after deployment without rebuilding the entire site. This is useful for pages that get frequent updates, such as blog posts or product listings.

import { GetStaticProps } from 'next';

type ProductProps = {
  name: string;
  price: number;
};

export default function Product({ name, price }: ProductProps) {
  return (
    <div>
      <h1>{name}</h1>
      <p>Price: ${price}</p>
    </div>
  );
}

export const getStaticProps: GetStaticProps = async () => {
  const product = await fetch('https://store.planstacker.com/product/1').then(res => res.json());

  return {
    props: {
      name: product.name,
      price: product.price,
    },
    revalidate: 30, // Regenerates the page every 30 seconds if data changes
  };
};

The above code demonstrates how ISR combines the best of SSG and SSR, keeping content fresh without slowing down performance. Note that the revalidate property allows you to specify the time (in seconds) after which the page should be regenerated.

Final Thoughts

• Use SSG for content that rarely changes to maximize speed.
• Use SSR only when real-time data is essential.
• Use ISR to keep frequently updated content fresh without affecting performance.

By implementing these strategies, your Next.js application will be faster, more scalable, and efficient at handling dynamic content without unnecessary server load.

3. Implement API Caching and Revalidation

Efficient API caching and revalidation can significantly improve the performance and scalability of your Next.js application. Instead of making frequent API requests, you can cache responses and refresh them only when necessary. This reduces server load, speeds up response times, and ensures users get the latest data when needed.

Use Incremental Static Regeneration (ISR) for API Data

One of the simplest ways to cache API responses is by using Incremental Static Regeneration (ISR) in Next.js. This ensures that pages displaying API data are pre-built and only refreshed after a set time.

Example: Fetching and Caching Blog Posts Data

import { GetStaticProps } from 'next';

type BlogPost = {
  id: number;
  title: string;
  content: string;
};

type BlogProps = {
  posts: BlogPost[];
};

export default function Blog({ posts }: BlogProps) {
  return (
    <div>
      <h1>Latest Blog Posts</h1>
      {posts.map((post) => (
        <article key={post.id}>
          <h2>{post.title}</h2>
          <p>{post.content}</p>
        </article>
      ))}
    </div>
  );
}

export const getStaticProps: GetStaticProps = async () => {
  const posts = await fetch('https://blog.planstacker.com/blog-posts').then((res) => res.json());

  return {
    props: {
      posts,
    },
    revalidate: 60, // Revalidates every 60 seconds
  };
};

Why use ISR for API caching? This method ensures that your page is always up to date while avoiding unnecessary API requests.

Use API Routes with Conditional Revalidation

For API responses that should be refreshed on-demand, Next.js provides a way to invalidate the cache manually using res.setHeader().

Example: Caching API Responses with Conditional Revalidation

import { NextApiRequest, NextApiResponse } from 'next';

export default async function handler(req: NextApiRequest, res: NextApiResponse) {
  const cacheTime = 60; // Cache API response for 60 seconds
  res.setHeader('Cache-Control', `s-maxage=${cacheTime}, stale-while-revalidate`);

  const data = await fetch('https://api.planstacker.com/data').then(res => res.json());

  res.status(200).json(data);
}

The above example shows the API response is cached for 60 seconds, reducing load on the external API. If a request comes in after 60 seconds, Next.js serves the stale data while fetching the latest version in the background.

Leverage Edge Caching for Faster Global Performance

If your API serves users worldwide, using Next.js Edge Functions can drastically improve performance by caching responses at the edge, closer to users.

Example: Edge API Route with Cache-Control

import { NextRequest, NextResponse } from 'next/server';

export const config = {
  runtime: 'edge',
};

export default async function handler(req: NextRequest) {
  const cacheTime = 120; // Cache for 120 seconds
  const response = await fetch('https://api.example.com/data');

  const res = new NextResponse(response.body, {
    status: response.status,
    headers: {
      'Cache-Control': `s-maxage=${cacheTime}, stale-while-revalidate`,
    },
  });

  return res;
}

Why use Edge Functions? They enable ultra-fast API responses by caching at multiple locations worldwide, reducing latency for users.

Final Thoughts

• Use ISR to cache API responses in static pages and regenerate them only when needed.
• Use API Route caching (Cache-Control) to store API responses and reduce backend load.
• Leverage Edge Functions to cache API responses globally for faster access.

By implementing these caching strategies, your Next.js app will deliver a faster, more scalable, and cost-efficient experience while minimizing redundant API requests.

4. Leverage Edge Functions and Middleware

Optimizing your Next.js app for speed and scalability isn’t just about caching API responses—it’s also about reducing server response times and handling requests efficiently. Edge functions and middleware allow you to process requests closer to the user, improving performance without overloading your backend.

In section 3 we discussed how Edge Functions help cache API responses globally, reducing latency for users accessing dynamic data. This ensures faster data fetching and minimal backend strain.

In this section, we go beyond caching and focus on how Edge Functions and Middleware can:

Optimize request handling with middleware for authentication, A/B testing, and personalization.

Reduce server response time by running code at the edge before reaching your API.

Reduce Server Response Time with Edge Functions

Edge Functions execute before a request reaches your API or server-side logic. This enables faster request processing by handling lightweight tasks such as:

• Redirecting users based on location or device
• Filtering requests before hitting your backend

Example: Redirect Users Based on Location at the Edge

import { NextRequest, NextResponse } from 'next/server';

export const config = {
  runtime: 'edge',
};

export default function handler(req: NextRequest) {
  const country = req.geo?.country || 'US';

  if (country === 'US') {
    return NextResponse.redirect('https://planstacker.com/usa');
  }

  return NextResponse.next();
}

Why use this? If a user from US visits the site, they are instantly redirected to a localized version—without waiting for a server response.

Use Middleware for Authentication and A/B Testing

Middleware in Next.js runs before a request is completed, allowing you to modify responses dynamically. This is ideal for:

• Authentication checks (e.g., blocking unauthorized users before reaching the app)
• A/B testing (e.g., serving different versions of a page for experimentation)

Example: Protecting Routes with Middleware Authentication

import { NextRequest, NextResponse } from 'next/server';

export function middleware(req: NextRequest) {
  const token = req.cookies.get('authToken');

  if (!token) {
    return NextResponse.redirect('/login');
  }

  return NextResponse.next();
}

export const config = {
  matcher: '/dashboard/:path*', // Apply middleware to all dashboard routes
};

Why use this? Unauthenticated users trying to access the dashboard are redirected to the login page before the request reaches your API or page logic.

By leveraging both Edge Functions and Middleware, you can significantly improve performance, security, and user experience while minimizing unnecessary server processing.

5. Optimize JavaScript & Bundle Size

Reducing JavaScript size and optimizing bundle delivery are crucial for a fast Next.js app. Large scripts slow down performance, increase time-to-interactive, and impact SEO.

Key Optimization Strategies:

• Tree-shaking: Remove unused JavaScript during bundling.
• Dynamic Imports: Load JavaScript only when needed.
• Code Splitting: Split large components into smaller, on-demand chunks.

Example: Dynamic Import for Reducing Bundle Size

import dynamic from 'next/dynamic';

// Load Chart component only when needed
const Chart = dynamic(() => import('@/components/Chart'), { ssr: false });

export default function Dashboard() {
  return (
    <div>
      <h1>Dashboard</h1>
      <Chart />
    </div>
  );
}

So, the above code shows the Chart component loads only when the Dashboard page is visited, reducing unnecessary JavaScript on initial load.

Other Quick Wins:

Use next/script for third-party scripts to control when they load.

Analyze your bundle with next build && next analyze.

Remove unnecessary polyfills and libraries.

6. Use Server Actions & Streaming for Faster Interactions

Next.js 14 introduces Server Actions and Streaming, allowing you to reduce client-side work by handling logic directly on the server. This improves load speed, performance, and interactivity.

Key Benefits:

• Faster API calls – No need for separate API endpoints.
• Streaming UI updates – Load components progressively for a smoother experience.

Example: Using a Server Action for Form Submission

"use server";

import { revalidatePath } from "next/cache";

export async function createPost(formData: FormData) {
  const res = await fetch("https://api.planstacker.com/posts", {
    method: "POST",
    body: formData,
  });

  if (res.ok) {
    revalidatePath("/blog"); // Refresh the blog page after submission
  }
}

Instead of making an API request from the client, the form submits directly to the server, reducing unnecessary JavaScript execution on the client side.

Conclusion

Optimizing a Next.js application for speed and scalability isn’t about a single fix—it’s about making incremental improvements across multiple areas.

In this guide, we explored six essential strategies to enhance your app’s performance:

1. Optimize Image Loading – Use the Next.js <Image> component for automatic optimizations.
2. Enable Automatic Static Optimization – Leverage SSG and ISR to reduce backend load.
3. Implement API Caching and Revalidation – Reduce latency with smart caching strategies.
4. Leverage Edge Functions and Middleware – Improve request handling at the edge for faster responses.
5. Optimize JavaScript & Bundle Size – Reduce unused JavaScript and enable dynamic imports.
6. Use Server Actions & Streaming – Minimize API calls and improve interactivity with server-side execution.

By applying these techniques, your Next.js application will be faster, more efficient, and ready to scale—ensuring a seamless experience for users while reducing server strain. Start optimizing today and future-proof your platform for growth.