Web Performance: Core Web Vitals Explained

Fast websites get more traffic. Google measures speed using "Core Web Vitals".

LCP (Largest Contentful Paint)

What: How long it takes for the main content (hero image, heading) to load. Goal: Under 2.5 seconds. Fix: Optimize images (WebP), use CDNs, cache assets.

FID (First Input Delay) / INP

What: Responsiveness. When a user clicks a button, how long until the browser reacts? Goal: Under 100ms. Fix: Reduce JavaScript bloat, break up long tasks.

CLS (Cumulative Layout Shift)

What: Visual stability. Does the text jump when an ad loads? Goal: Under 0.1. Fix: Define explicit width and height for all images and videos.

Tools to Measure

1. Lighthouse: Built into Chrome DevTools.
2. PageSpeed Insights: Google's official tool.

Focusing on these metrics isn't just about SEO; it's about respecting your user's time.