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Advanced 16 min readModule: Module 8: Optimizing Images, Fonts & Scripts

Core Web Vitals Optimization (next/image, next/font)

Achieve 100/100 Google Lighthouse scores using Next.js automatic image optimization and self-hosted fonts.

What You Will Learn in This Lesson

  • Automatic AVIF/WebP image conversion and responsive sizing with <Image />
  • Zero layout shift (CLS) self-hosted fonts with next/font/google
  • Third-party script loading strategies with next/script

Introduction & Core Concept

Next.js includes built-in components that automatically optimize media assets, fonts, and scripts to pass Google Core Web Vitals.
WHY DOES THIS MATTER IN THE REAL WORLD?

next/image serves appropriately sized images for each user device, saving over 80% bandwidth on mobile.

Optimized Image Component

typescript
typescript
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import Image from "next/image";
 
export function HeroBanner() {
  return (
    <Image
      src="/hero.png"
      alt="KWAS Academy Cloud Platform"
      width={1200}
      height={630}
      priority // Preloads for Largest Contentful Paint (LCP)
    />
  );
}

Line-by-Line Technical Breakdown

1next/font automatically downloads and self-hosts Google Fonts at build time with zero external network requests.

Try It Yourself (Interactive Editor)

Modify the code in real-time and click Run to test live browser output and console logs.

Intelligent Code Runner & Live Sandbox[TYPESCRIPT]
TYPESCRIPT SOURCE EDITOR
Interactive Live Code

Industry Best Practices & Professional Standards

  • Always add 'priority' to above-the-fold hero images.

Lesson Summary & Core Takeaways

  • Next.js optimizations automate peak performance and Core Web Vitals compliance.