What Are Core Web Vitals?
Google uses three primary page-experience metrics: LCP (Largest Contentful Paint), INP (Interaction to Next Paint), and CLS (Cumulative Layout Shift). INP replaced FID in 2024.
LCP Optimization (< 2.5s)
LCP measures the render time of the largest visible element on the page — typically a hero image or a prominent heading.
Fixes: Serve images as WebP/AVIF. Inline critical CSS. Load fonts with font-display: swap. Keep server response time (TTFB) below 200ms. Use a CDN.
INP Optimization (< 200ms)
INP measures how quickly the page responds to user interactions — clicks, taps, and key presses. Keeping the JavaScript main thread unblocked is critical.
Fixes: Break long tasks with requestIdleCallback or scheduler.yield(). Keep event handlers light. Load third-party scripts with defer or async.
CLS Optimization (< 0.1)
CLS measures unexpected layout shifts during page load. Ads, late-loading images, and font swaps are the most common culprits.
Fixes: Set explicit width and height on all images. Use size-adjust for fonts. Reserve space with placeholders for dynamic content.
Conclusion
Core Web Vitals matter for both SEO and user experience. Review the CWV report in Google Search Console regularly — it is one of the dashboards KEYDAL always keeps open.