Google's Core Web Vitals (CWV) are no longer just an abstract developer metric. They are a confirmed ranking factor and directly correlate with checkout conversion rates and bounce rates.
1. Largest Contentful Paint (LCP) < 1.8s
Prioritize Hero Assets: Ensure critical above-the-fold images use priority and modern WebP/AVIF formats.
Stream SSR HTML: Utilize React Server Components (RSC) to stream static layout structures instantly while asynchronously fetching slower background data.
2. Interaction to Next Paint (INP) < 200ms
Replace heavy JavaScript computation on the main thread with Web Workers or debounced handlers.
Defer non-critical analytics and chat widget scripts until after user interaction.
3. Cumulative Layout Shift (CLS) < 0.05
Always specify explicit width and height aspect ratios on images and video containers.
Reserve reserved skeleton containers for dynamic API data and banner advertisements to avoid sudden reflows.