Core Web Vitals (CLS, FID, LCP) are Google's key metrics for measuring user experience and SEO. CLS measures layout stability, FID measures interactivity, and LCP measures visual load speed. To improve CLS: add width/height attributes to images, preload fonts and hero images, use font-display: optional for non-critical fonts, and reserve space for JS-injected content. To improve LCP: use loading='eager' and importance='high' on key images, preload critical resources in the head, reduce server response time (TTFB), and use preconnect/dns-prefetch for third-party domains. The post also demonstrates how Polypane's built-in visualizations highlight which specific elements contribute to CLS and LCP scores.
2 Impressions