Website performance directly impacts user experience and search engine rankings. Learn how to optimize your site for speed.

Understanding Core Web Vitals

Core Web Vitals are key metrics that Google uses to evaluate page experience.

Largest Contentful Paint (LCP)

LCP measures loading performance. Aim for LCP to occur within 2.5 seconds.

• Optimize server response time
• Optimize critical rendering path
• Improve resource load times
• Use Content Delivery Networks (CDNs)

First Input Delay (FID)

FID measures interactivity. Keep FID below 100 milliseconds.

• Reduce JavaScript execution time
• Break up long JavaScript tasks
• Use web workers for heavy computation
• Optimize third-party scripts

Cumulative Layout Shift (CLS)

CLS measures visual stability. Keep CLS score under 0.1.

• Reserve space for images and ads
• Avoid inserting content above existing content
• Use transform animations instead of layout changes

Image Optimization

Images often account for the majority of page load time.

Best Practices

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<!-- Use modern formats -->
<picture>
    <source srcset="image.webp" type="image/webp">
    <img src="image.jpg" alt="Description">
</picture>

<!-- Responsive images -->
<img srcset="small.jpg 600w, large.jpg 1200w" 
     sizes="(max-width: 600px) 100vw, 1200px"
     src="large.jpg" alt="Description">

Code Splitting and Lazy Loading

Reduce initial bundle size with code splitting.

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// Dynamic imports for route-based splitting
const Component = lazy(() => import('./Component'));

// Intersection Observer for lazy loading
const observer = new IntersectionObserver((entries) => {
    entries.forEach(entry => {
        if (entry.isIntersecting) {
            loadContent();
        }
    });
});

Caching Strategies

Implement effective caching to reduce server load.

• Browser caching with cache headers
• Service workers for offline support
• CDN caching for static assets
• Database query caching

Tools for Performance Testing

• Google PageSpeed Insights
• WebPageTest
• Lighthouse
• GTmetrix

Website performance optimization is an ongoing process that yields significant returns.