Skip to main content

Lighthouse Audits and Performance Optimization

Lighthouse is a powerful tool by Google that helps developers identify performance issues, accessibility problems, and best practices for Progressive Web Apps (PWAs). In this tutorial, we will cover how to use Lighthouse to audit your React PWA and optimize its performance.

Running a Lighthouse Audit

  1. Install the Lighthouse CLI:
npm install -g lighthouse
  1. Build your React PWA for production:
npm run build
  1. Serve your production build locally:
npm install -g serve
serve -s build
  1. Run a Lighthouse audit:
lighthouse http://localhost:5000 --view

This command will generate a detailed report, which will open in your default web browser.

Analyzing the Lighthouse Report

The Lighthouse report is divided into several categories, such as Performance, Accessibility, Best Practices, SEO, and Progressive Web App. Each category has a score out of 100, and Lighthouse provides detailed information and recommendations for improvement.

Performance Optimization

Based on the Lighthouse report, follow the recommendations to optimize your React PWA. Here are some common suggestions:

  1. Minify and compress files: Make sure your JavaScript, CSS, and HTML files are minified and compressed using tools like Terser, CSSNano, and HTMLMinifier.

  2. Optimize images: Compress images without losing quality using tools like ImageOptim or TinyPNG. Use modern image formats like WebP for better compression.

  3. Code splitting: Use React.lazy and Suspense to split your code into smaller chunks and load them on demand.

  4. Eliminate render-blocking resources: Inline critical CSS and defer non-critical CSS. Use async or defer attributes for non-critical JavaScript files.

  5. Use a Content Delivery Network (CDN): Serve your static assets through a CDN for faster delivery and reduced latency.


By using Lighthouse to audit your React PWA, you can identify performance bottlenecks and optimize your app for the best user experience. Remember to run Lighthouse audits periodically and address any issues to ensure your PWA remains efficient and accessible.