Why It Matters

Core Web Vitals are part of Google’s page experience signals. They’re a modest ranking factor compared with relevance, but poor scores reflect real visitor friction that costs conversions.

  1. Largest Contentful Paint (LCP < 2.5s): Preload the hero image using <link rel="preload" as="image"> or give it fetchpriority="high", never lazy-load it, optimize server response time, and compress main page media.

  2. Cumulative Layout Shift (CLS < 0.1): Specify explicit width and height attributes on all image and iframe tags to reserve layout space during loading.

  3. Interaction to Next Paint (INP < 200ms): Break up long JavaScript tasks into smaller ones (or move heavy work to a web worker), remove heavy main-thread blocking code, and defer non-critical scripts.

How to Check It Worked

Google judges Core Web Vitals on real visitors’ experience, measured at the 75th percentile over the previous 28 days. Check the Core Web Vitals report in Google Search Console or the field data at the top of PageSpeed Insights; lab scores from one test can differ, and improvements take up to a month to show.