Web Performance Optimization Guide

Introduction

Web performance is critical for user experience and SEO. This guide covers actionable strategies to optimize your web applications.

Core Web Vitals

Google's Core Web Vitals measure user experience across three key areas:

1. Largest Contentful Paint (LCP)

• Measures visual completeness
• Target: < 2.5 seconds
• Optimize: Images, fonts, lazy loading

2. First Input Delay (FID)

• Measures interactivity
• Target: < 100 milliseconds
• Optimize: JavaScript execution, long tasks

3. Cumulative Layout Shift (CLS)

• Measures visual stability
• Target: < 0.1
• Optimize: Reserve space, avoid unsized media

Performance Optimization Techniques

Code Splitting

// Dynamic imports for route-based splitting
const Dashboard = dynamic(() => import('./Dashboard'), {
  loading: () => <LoadingSpinner />,
});

Image Optimization

• Use next/image component
• Serve appropriate sizes
• Use modern formats (WebP)
• Implement lazy loading

JavaScript Bundling

• Minimize main bundle
• Remove unused code
• Tree-shake dependencies
• Compress assets

Monitoring Performance

Implement performance monitoring tools:

• Web Vitals API
• Google Analytics
• Lighthouse CI
• Custom metrics

Caching Strategies

• Browser caching
• CDN caching
• Service worker caching
• API response caching

Conclusion

Prioritizing performance optimization creates better user experiences and improves SEO rankings. Monitor continuously and iterate based on real user data.