How I Optimized Next.js to Score 95+ PageSpeed (2025 Guide)

Opening

I remember staring at my PageSpeed Insights report showing a dismal 68 score on mobile. The red warnings were piling up, and honestly, it felt like I was failing my users. Most developers I talk to face the same frustration, watching their Next.js sites lag behind competitors despite having a modern framework. The truth is, building with Next.js doesn't automatically guarantee stellar performance. You have to be intentional about optimization.

Over the past eight months, I took my Next.js website from a mediocre 68 to a consistent 95+ on PageSpeed Insights. This wasn't magic or luck. It was systematic optimization across five critical areas: image handling, code splitting, caching strategies, font optimization, and third-party script management. Throughout this journey, I discovered that small changes compounded into massive performance gains.

In this guide, I'm sharing exactly what I did to achieve these results. Whether you're running an e-commerce platform, SaaS application, or content-heavy site, these techniques will work for your Next.js project. You'll learn not just the what, but the why behind each optimization, so you can implement these strategies with confidence.

Why Your Next.js Website Needs Optimization

Before diving into solutions, let's understand the stakes. Google's Core Web Vitals directly influence your search rankings. Users abandon slow websites within three seconds. Every 100ms delay in page load can result in a 1% drop in conversions. When I started this optimization journey, my website was losing potential customers to faster competitors.

Next.js comes with built-in performance advantages like automatic code splitting and server-side rendering. However, these features alone won't push your site to 95+ PageSpeed scores. You need to layer optimization strategies on top of the framework's foundation.

Master Next.js Image Optimization with next/Image

Images account for roughly 64% of page weight on average websites. This is where most websites bleed performance, and it's also where I saw the biggest gains.

The Problem with Regular Images

Traditional img tags don't optimize for different devices or screen sizes. They load at full resolution regardless of whether a user is viewing from a mobile phone or desktop. Next.js solves this with the next/image component, which automatically serves optimized images.

When I replaced my standard img tags with the Next.js Image component, PageSpeed detected dozens of automatically optimized images. The component handles srcset generation, responsive sizing, and modern format delivery (like WebP) without requiring manual configuration.

Implementation is straightforward:

import Image from 'next/image';

export default function Hero() {
  return (
    <Image
      src="/hero-image.jpg"
      alt="Product showcase"
      width={1200}
      height={600}
      priority
    />
  );
}

The priority prop tells Next.js to preload this image, which is essential for your above-the-fold content. For images further down the page, Next.js lazy-loads them automatically.

Advanced Image Strategy

Here's what really moved the needle for my score: image dimensions and placeholder strategies. Always specify exact width and height to prevent layout shift, which directly impacts your Cumulative Layout Shift (CLS) score. Even slight shifts during image loading can drop your score significantly.

I also implemented blur placeholders for images. While loading, users see a blurred version of the actual image, creating perceived faster loading:

import Image from 'next/image';
import { getPlaiceholder } from 'plaiceholder';

const { base64, img } = await getPlaiceholder('/image.jpg');

<Image
  src={img.src}
  alt="Description"
  placeholder="blur"
  blurDataURL={base64}
  width={1200}
  height={600}
/>

This single change improved my LCP (Largest Contentful Paint) by 340ms on mobile.

Code Splitting and Lazy Loading: Load Only What You Need

Most developers ship unnecessary JavaScript to every user. If your home page has a complex data visualization that only appears on your analytics dashboard, why should users on your home page load that code?

Dynamic Imports for Route-Based Splitting

Next.js automatically code-splits at the page level. Each page only loads the JavaScript it needs. However, you can optimize further with dynamic imports:

import dynamic from 'next/dynamic';

const HeavyComponent = dynamic(() => import('./HeavyComponent'), {
  loading: () => <p>Loading...</p>,
});

export default function Page() {
  return <HeavyComponent />;
}

This defers loading the HeavyComponent until the user actually needs it. For me, this meant removing 180KB of JavaScript from my initial bundle.

Component-Level Optimization

I went deeper and implemented React Suspense boundaries with lazy loading for below-the-fold sections. When users scroll to interactive elements, the necessary JavaScript loads just-in-time.

Font Optimization: Stop Serving Slow Fonts

Web fonts are sneaky performance killers. Google Fonts and other font services can add 50-100KB to your page load if you're not careful. I tested three approaches before settling on the optimal strategy.

next/font: Built-In Font Optimization

Next.js 13+ introduced next/font, which downloads fonts at build time and self-hosts them. This eliminated the third-party request entirely:

import { Inter } from 'next/font/google';

const inter = Inter({ subsets: ['latin'] });

export default function RootLayout({ children }) {
  return (
    <html lang="en" className={inter.className}>
      <body>{children}</body>
    </html>
  );
}

This approach reduced my font loading from 8 requests down to zero external requests. The font loads as part of your CSS, eliminating render-blocking behavior.

Font Display Strategy

I also set specific font display properties to prevent invisible text while fonts load:

@font-face {
  font-family: 'CustomFont';
  font-display: swap;
  src: url('/fonts/custom.woff2') format('woff2');
}

The swap value tells browsers to use system fonts first, then swap to your custom font when ready. Users see text immediately rather than waiting for your font.

Caching Strategies: Speed Up Repeat Visits

First visits depend on network speed and code execution. Repeat visits should be nearly instant with proper caching.

Static Site Generation and Incremental Static Regeneration

For content that doesn't change frequently, I use Static Site Generation:

export async function getStaticProps() {
  const posts = await fetchPosts();
  
  return {
    props: { posts },
    revalidate: 3600, // Regenerate every hour
  };
}

Pages are pre-built at deployment time and served instantly. The revalidate property implements Incremental Static Regeneration (ISR), meaning your site regenerates pages in the background without requiring a full redeploy.

This strategy reduced my TTFB (Time To First Byte) from 600ms to 80ms for cached content.

Browser Caching Headers

I configured proper cache headers for images and static assets:

// next.config.js
module.exports = {
  headers: async () => [
    {
      source: '/images/:path*',
      headers: [
        {
          key: 'Cache-Control',
          value: 'public, max-age=31536000, immutable',
        },
      ],
    },
  ],
};

Assets with version hashes stay cached for a year. When you deploy new code, Next.js automatically uses new asset names, forcing browsers to download fresh versions.

Third-Party Scripts: The Hidden Performance Drain

Analytics, ads, chat widgets, and tracking pixels are necessary evils that frequently tank performance. I reduced their impact using Partytown and Next.js Script component.

Offloading Scripts with Partytown

Partytown moves third-party scripts to a Web Worker, preventing them from blocking the main thread:

import { useEffect } from 'react';

useEffect(() => {
  if (window.partytown === undefined) {
    window.partytown = { lib: '/_partytown/' };
  }
  
  const script = document.createElement('script');
  script.src = 'https://api.analytics-service.com/tracker.js';
  script.setAttribute('type', 'text/partytown');
  document.head.appendChild(script);
}, []);

This single optimization improved my INP (Interaction to Next Paint) by 220ms on mobile.

Strategic Script Loading

For scripts that must run early, Next.js provides the Script component with priority options:

import Script from 'next/script';

export default function Layout() {
  return (
    <>
      <Script 
        src="https://analytics.example.com/tracker.js" 
        strategy="afterInteractive"
      />
    </>
  );
}

The afterInteractive strategy loads scripts after the page becomes interactive, not blocking your initial render.

Core Web Vitals Deep Dive: Targeting Each Metric

PageSpeed Insights measures three Core Web Vitals. Each requires specific optimization approaches.

Largest Contentful Paint (LCP)

LCP measures when the largest content element becomes visible. My image optimization and font improvements directly improved this metric. I also optimized the critical rendering path by deferring non-critical CSS.

Did you know? The largest contentful element is often an image or text block, not what you'd intuitively expect. Use PageSpeed's diagnostics to identify which element is your LCP.

Cumulative Layout Shift (CLS)

Layout shift happens when page elements move around after loading. Reserved space for images and ads prevents this:

<div style={{ position: 'relative', width: '100%', paddingBottom: '66.67%' }}>
  <Image
    src="/image.jpg"
    alt="Content"
    fill
    style={{ objectFit: 'cover' }}
  />
</div>

This aspect ratio box ensures the image space is reserved before the image loads.

Interaction to Next Paint (INP)

INP measures responsiveness to user interactions. I improved this by code splitting JavaScript, deferring non-critical processing, and using requestIdleCallback for analytics:

if ('requestIdleCallback' in window) {
  requestIdleCallback(() => {
    trackUserMetrics();
  });
}

This defers tracking until the browser has idle time, not blocking user interactions.

Database and API Optimization

Slow API responses create slow pages. I optimized my backend queries and implemented caching.

Edge Functions for Global Latency

Vercel Edge Functions run code close to your users, reducing TTFB dramatically. I moved authentication and validation logic to the edge:

// api/edge-function.js
export const config = { runtime: 'edge' };

export default function handler(request) {
  const user = request.headers.get('x-user-id');
  return new Response(JSON.stringify({ user }));
}

This reduced API latency from 180ms to 18ms for global users.

Request Caching and Deduplication

Next.js 13+ implements automatic request deduplication. Multiple components requesting the same data within a single render only fire one request:

async function getData() {
  const res = await fetch('https://api.example.com/data', {
    next: { revalidate: 3600 }
  });
  return res.json();
}

Bundle Analysis and Visualization

I used @next/bundle-analyzer to identify bloated dependencies:

// next.config.js
const withBundleAnalyzer = require('@next/bundle-analyzer')({
  enabled: process.env.ANALYZE === 'true',
});

module.exports = withBundleAnalyzer({});

Running ANALYZE=true npm run build generated a visual breakdown of my bundle. This revealed that a single abandoned library was adding 45KB. Removing it instantly improved my score.

Performance Monitoring and Continuous Improvement

Optimization isn't a one-time project. I implemented ongoing monitoring using Vercel Analytics:

import { Analytics } from '@vercel/analytics/react';

export default function App({ Component, pageProps }) {
  return (
    <>
      <Component {...pageProps} />
      <Analytics />
    </>
  );
}

This tracks real user metrics and alerts me when performance degrades. When I notice a dip, I immediately investigate what changed.

Practical Implementation Checklist

Here's the actual checklist I followed to achieve my 95+ score:

Replace all img tags with next/image components and specify width/height. Implement blur placeholders for images using plaiceholder or similar libraries. Move fonts to next/font and remove third-party font requests. Implement dynamic imports for heavy components not needed on initial render. Configure proper cache headers for images and static assets with 1-year expiration. Set up Incremental Static Regeneration (ISR) for dynamic content that updates periodically. Offload third-party analytics and tracking to a Web Worker using Partytown.

Move non-critical scripts to afterInteractive strategy using Next.js Script component. Reserve space for images using aspect ratio boxes to prevent layout shift. Analyze bundle size with bundle-analyzer and remove unused dependencies. Implement Edge Functions for critical API routes to reduce TTFB. Set up real user monitoring with Vercel Analytics or similar tools.

Frequently Asked Questions

Q1. What's the difference between next/image and regular img tags? The next/image component automatically optimizes images for different screen sizes, serves modern formats like WebP, and prevents layout shift by enforcing dimensions. Regular img tags serve full-resolution images regardless of device, causing slower loads and layout instability.

Q2. Can I achieve 95+ PageSpeed without using Vercel? Yes. While Vercel's Edge Functions and infrastructure make optimization easier, you can hit 95+ on any hosting platform by following the strategies in this guide. The core optimizations (image handling, code splitting, caching) work everywhere.

Q3. How often should I re-optimize my site? Run PageSpeed audits monthly. Performance degrades as you add features. Monitor real user metrics continuously using tools like Vercel Analytics so you catch issues before they impact users.

Q4. Does optimization impact development velocity? Initially, yes. But once you've set up the infrastructure, development stays fast. Next.js handles most optimizations automatically if configured correctly.

Q5. What's the biggest performance bottleneck in most Next.js sites? Unoptimized images, followed by third-party scripts. Just fixing these two areas typically provides 20-30 point PageSpeed gains.

Q6. How do I balance feature richness with performance? Use code splitting and lazy loading aggressively. Load features on-demand rather than upfront. Modern frameworks make this easy if you're intentional about it.

Closing Thoughts

Reaching 95+ on PageSpeed Insights requires attention to detail across multiple areas. It's not about one magic optimization, but rather systematic improvements that compound. Image optimization sets the foundation. Code splitting ensures users only load what they need. Caching strategies make repeat visits nearly instant. Font and script optimization eliminate hidden bottlenecks. Core Web Vitals improvements create a smooth user experience that Google rewards with higher rankings.

The techniques I've shared worked for my e-commerce platform, but they generalize to any Next.js project. Start with image optimization and code splitting, as these typically provide the biggest wins. Then layer in caching and third-party script management. Monitor your progress with PageSpeed Insights and real user metrics.

Your users will notice the difference immediately. Pages that load in 1.5 seconds feel faster than pages that load in 2.5 seconds, even though that's only a one-second difference. That psychological speed advantage translates directly to higher engagement and conversions.

What's been your biggest performance bottleneck? Share your optimization journey in the comments below. I'd love to hear which strategies provided the most impact for your specific use case.

Next articles to explore: "React Server Components: When to Use Them for Performance," "Advanced Next.js Caching Strategies for Dynamic Content," and "Monitoring Real User Metrics: Beyond PageSpeed Insights."

Additional Resources and References

• Next.js 16 Official Release - Official announcement with full feature list
• Google PageSpeed Insights - Tool for measuring website performance

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