A Practical Core Web Vitals Checklist for Marketing Websites | Tag Easy Journal

Core Web Vitals are a ranking and conversion signal. This is the practical checklist we use to ship fast, stable pages — especially on mobile.

Core Web Vitals measure real-world page experience: loading (Largest Contentful Paint), interactivity (Interaction to Next Paint), and visual stability (Cumulative Layout Shift). They influence both rankings and conversions, and mobile is where most sites struggle.

LCP is usually the hero image or headline. Give the hero a lightweight poster image, avoid autoplaying heavy video on mobile, preload the critical asset, and defer render-blocking fonts with `media="print" onload="this.media='all'"`. Serve modern formats (WebP/AVIF) and correctly sized images.

CLS happens when content jumps as the page loads. The single biggest fix is putting explicit `width` and `height` (or an aspect-ratio) on every image and media element so the browser reserves space before the asset arrives. Reserve space for embeds and avoid injecting content above existing content.