🎨 React Asset Optimization Guide

Optimizing assets (images, fonts, and other static files) in a React app improves performance, reduces load time, and enhances the user experience. Below are best practices for optimizing assets in your React project.

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🔹 Step 1: Optimize Images

Large images can significantly slow down your website. Use the following strategies:

✅ Use Modern Image Formats (WebP, AVIF)

WebP and AVIF offer better compression and smaller file sizes compared to PNG/JPEG.

<img src="image.webp" alt="Optimized Image" />

✅ Enable Lazy Loading

Lazy loading ensures that images load only when they are in the viewport.

<img src="large-image.jpg" loading="lazy" alt="Lazy Loaded Image" />

✅ Use Responsive Images

Use different image sizes for different screen resolutions.

<picture>
  <source srcSet="image-small.webp" media="(max-width: 600px)" />
  <source srcSet="image-large.webp" media="(min-width: 601px)" />
  <img src="image-fallback.jpg" alt="Responsive Image" />
</picture>

✅ Compress Images

Use tools like:

• TinyPNG (https://tinypng.com)
• ImageOptim (https://imageoptim.com)
• Squoosh (https://squoosh.app)

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🔹 Step 2: Optimize Fonts

Fonts can be a hidden performance bottleneck if not optimized.

✅ Use System Fonts (Avoid Large Font Files)

System fonts don’t require downloads, improving load times.

font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto;

✅ Use Font Subsetting

Only include the characters you need.

✅ Self-Host Fonts or Use Google Fonts with Display Swap

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

If using Google Fonts, add display=swap to prevent render-blocking.

<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Roboto&display=swap" />

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🔹 Step 3: Optimize CSS and JS Assets

✅ Minify CSS and JavaScript

Use tools like Terser and CSSNano.

npm install terser cssnano --save-dev

For Webpack, enable minification:

optimization: {
  minimize: true,
  minimizer: [new TerserPlugin()],
}

✅ Remove Unused CSS

If using Tailwind CSS, enable PurgeCSS to remove unused styles:

module.exports = {
  purge: ["./src/**/*.js", "./public/index.html"],
};

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🔹 Step 4: Use Content Delivery Network (CDN)

A CDN caches assets across global servers for faster load times.

• Use Cloudflare, Netlify, or AWS S3 + CloudFront.
• Store static assets like images, fonts, and videos on a CDN.

<img src="https://cdn.example.com/images/optimized-image.webp" alt="CDN Image" />

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🔹 Step 5: Enable Gzip or Brotli Compression

Compressed assets load faster by reducing file size.

✅ Enable Brotli Compression in Vite

npm install vite-plugin-compression

Modify vite.config.js:

import compression from "vite-plugin-compression";
export default {
  plugins: [compression()],
};

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✅ Summary: Key Steps for Asset Optimization

Optimization	Method
Optimize Images	Use WebP/AVIF, Lazy Loading, Compression
Optimize Fonts	Use System Fonts, Subset Fonts, Font Display Swap
Minify CSS & JS	Terser, CSSNano, PurgeCSS for Tailwind
Use a CDN	Store static assets on a CDN
Enable Compression	Gzip/Brotli via Webpack or Vite

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