Core Web Vitals

Core Web Vitals are a set of specific factors that Google considers important in a webpage's overall user experience. They are:

- Largest Contentful Paint (LCP): Loading performance - First Input Delay (FID): Interactivity - Cumulative Layout Shift (CLS): Visual stability

These metrics are critical for SEO as they are direct ranking factors in Google's algorithm.

LCP measures loading performance - specifically, how quickly the largest content element becomes visible:

- Target: Under 2.5 seconds - Common Issues: - Slow server response times - Render-blocking JavaScript and CSS - Slow resource load times - Client-side rendering

Optimization Techniques: - Implement server-side rendering or static generation - Optimize and compress images - Use a CDN for faster content delivery - Minimize critical CSS and defer non-critical CSS - Implement proper caching strategies

FID measures interactivity - the time from when a user first interacts with your page to when the browser responds:

- Target: Under 100 milliseconds - Common Issues: - Heavy JavaScript execution - Long tasks blocking the main thread - Too many third-party scripts - Large JavaScript bundles

Optimization Techniques: - Break up long tasks - Defer or remove non-critical JavaScript - Use a web worker for heavy computations - Implement code-splitting - Optimize third-party script loading

CLS measures visual stability - how much unexpected layout shift occurs during page loading:

- Target: Under 0.1 - Common Issues: - Images without dimensions - Ads, embeds, and iframes without reserved space - Dynamically injected content - Web fonts causing FOIT/FOUT

Optimization Techniques: - Always include width and height attributes on images - Reserve space for ads and embeds - Avoid inserting content above existing content - Preload key web fonts - Use font-display: optional or swap

Several tools are available for measuring Core Web Vitals:

- Chrome DevTools - Lighthouse - PageSpeed Insights - Chrome User Experience Report - Search Console Core Web Vitals report - web-vitals JavaScript library

Regular monitoring and testing across different devices and connection speeds is essential.

Follow these steps to improve your Core Web Vitals:

1. Measure current performance using available tools 2. Identify specific issues affecting each metric 3. Prioritize improvements based on impact 4. Implement optimizations systematically 5. Monitor results and iterate 6. Set up continuous monitoring

Remember that improvements should be maintained over time and tested regularly.