Core Web Vitals CWV

Why it matters

Slow, jumpy pages lose buyers before they read a word. Core Web Vitals turn that into three numbers you can fix. Google uses them as part of the page experience signals it considers in ranking, but it also says great content can outrank a faster page, so they are one input and not a trump card. The sound reason to care is conversions: a page that loads and responds quickly sells more.

The three metrics

• Largest Contentful Paint (LCP): how long the biggest visible element takes to appear. Good is 2.5 seconds or less.
• Interaction to Next Paint (INP): how quickly the page responds when someone taps or clicks. Good is 200 milliseconds or less.
• Cumulative Layout Shift (CLS): how much the layout jumps while loading. Good is 0.1 or less.

Each is judged at the 75th percentile of real visits, separately for mobile and desktop.

How to improve them

• LCP: compress and properly size the hero image, serve it in a modern format, avoid lazy-loading the first image and trim slow server responses.
• INP: remove or delay heavy third-party scripts such as chat widgets, tag-manager clutter and sliders.
• CLS: set width and height on images and embeds, and reserve space for banners and ads.
• Measure real users, not just a lab test: the Core Web Vitals report in Search Console and PageSpeed Insights show field data.

Common mistakes

• Testing only on your office wifi and laptop. Most of your visitors use mid-range phones on mobile data.
• Chasing a perfect 100 score. Passing the thresholds is the goal.
• Fixing the home page only, when the product and enquiry pages carry the revenue.

These feed the technical side of SEO and your conversion rate.