How I Made My Next.js App Load 10x Faster (And You Can Too)

Performance is crucial for any web application, especially for an app built with Next.js. A slow website leads to high bounce rates, poor user experience, and lower SEO rankings. In this blog, I'll walk you through how I optimized my Next.js app to load 10x faster and how you can achieve the same results.

🚀 The Problem: Why Was My Next.js App Slow?

Before optimization, my app suffered from the following issues:

• **Large J

vaScript bundles** causing long load times.

• Unoptimized images increasing page weight.
• Render-blocking scripts slowing down initial rendering.
• Poor caching strategy forcing unnecessary data fetches.
• Slow API responses delaying content rendering.
• Lack of code splitting making users download unused code.

After diagnosing these problems, I applied several optimizations that drastically improved performance.

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🔥 The Solutions: How I Optimized My Next.js App

1️⃣ Enable Automatic Static Optimization

Next.js automatically pre-renders pages whenever possible. To take full advantage of this:

export default function Home({ data }: { data: any }) {
  return <div>{data.title}</div>;
}

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

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

• getStaticProps ensures the page is built at compile time.
• ISR allows incremental updates without a full rebuild.

---

2️⃣ Optimize Images with Next.js Image Component

Images often account for 50% of a website’s total weight. Next.js has built-in image optimization:

import Image from 'next/image';

<Image src="/example.jpg" alt="Example" width={500} height={300} quality={75} />

• Automatic format conversion (WebP, AVIF, etc.).
• Lazy loading by default.
• Responsive images.

---

3️⃣ Reduce JavaScript Bundle Size with Dynamic Imports

To avoid shipping unnecessary JavaScript, code split large components:

import dynamic from 'next/dynamic';

const HeavyComponent = dynamic(() => import('../components/HeavyComponent'), {
  ssr: false,
});

This ensures the heavy component loads only when needed, reducing the initial bundle size.

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4️⃣ Use Server Components & RSC (React Server Components)

Next.js App Router supports React Server Components, reducing client-side JS:

export default async function Page() {
  const data = await fetchData();
  return <div>{data}</div>;
}

• Less JavaScript sent to the client.
• Better performance and SEO.
• Instant hydration improvements.

---

5️⃣ Implement Caching & Memoization

Expensive API calls should be cached using React Query, SWR, or Redis:

import useSWR from 'swr';

const fetcher = (url: string) => fetch(url).then((res) => res.json());

export default function Page() {
  const { data, error } = useSWR('/api/data', fetcher, {
    revalidateOnFocus: false,
  });

  if (error) return <div>Error loading data</div>;
  if (!data) return <div>Loading...</div>;

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

• useSWR caches and refetches only when necessary.
• Avoids unnecessary network requests.

---

6️⃣ Minimize Render-blocking Resources

To defer non-essential scripts, use:

<script src="/heavy-script.js" async />

OR load third-party libraries only when needed:

const HeavyLib = dynamic(() => import('heavy-lib'), { ssr: false });

---

7️⃣ Reduce CSS & JavaScript Payloads

Using Tailwind CSS and PurgeCSS, we removed unused styles:

"purge": ["./pages/**/*.tsx", "./components/**/*.tsx"]

Minimize JS size by:

• Tree shaking unused imports
• Avoiding large libraries (like lodash)
• Using lightweight alternatives

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8️⃣ Optimize API Calls with Edge Functions

Instead of relying on a slow backend, use Next.js Edge Functions:

export default function middleware(req) {
  return new Response('Hello from Edge!');
}

• Runs closer to the user, reducing latency.
• Great for A/B testing, authentication, and redirects.

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🎯 The Results: Before & After Optimization

Metric	Before Optimization	After Optimization
First Contentful Paint (FCP)	3.5s	1.2s
Largest Contentful Paint (LCP)	5.2s	1.5s
Time to Interactive (TTI)	6.8s	1.9s
JavaScript Payload	750KB	150KB
Image Load Time	4s	800ms

By implementing these eight optimizations, I achieved a 10x faster Next.js app.

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📌 Conclusion: Make Your Next.js App Faster Today!

If your Next.js app is slow, start with these steps: ✅ Enable Static Generation (SSG) & ISR ✅ Optimize Images with Next.js <Image /> ✅ Reduce JS bundle size using dynamic imports ✅ Use React Server Components for heavy data fetching ✅ Implement Caching & Memoization (SWR, React Query) ✅ Minimize Render-blocking Scripts & Unused Code ✅ Deploy APIs with Edge Functions for speed

By applying these techniques, you’ll see massive performance improvements. Try them out and watch your app load at lightning speed! ⚡

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