Core Web Vitals Optimization for Video Websites

Video websites are among the hardest to optimize for Core Web Vitals. Heavy thumbnails, dynamic content, and embedded players fight against every performance metric. Here's how I optimized TrendVidStream from a PageSpeed score of 50 to 71-90 on mobile. The Metrics That Matter LCP (Largest Contentful Paint): < 2.5s target CLS (Cumulative Layout Shift): < 0.1 target INP (Interaction to Next Paint): < 200ms target LCP Optimization The hero thumbnail is typically the LCP element on video sites. <!-- Prioritize the hero image --> <img src= "/thumb/hero.webp" alt= "Trending video thumbnail" width= "640" height= "360" fetchpriority= "high" decoding= "async" > <!-- Lazy-load below-fold thumbnails --> <img src= "/thumb/placeholder.svg" data-src= "/thumb/video2.webp" alt= "Video thumbnail" width= "320" height= "180" loading= "lazy" decoding= "async" > <?php // Preload critical hero image in HTTP headers function addPreloadHeaders ( string $heroThumb ): void { header ( "Link: < $heroThumb >; rel=