Core Web Vitals are three specific performance metrics Google uses to measure real-world user experience on your pages. As of March 2024, they are Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS). INP replaced First Input Delay (FID) because it captures responsiveness more accurately across the entire page visit, not just the first click. LCP measures loading performance. Your largest visible element (usually a hero image or heading block) should render within 2.5 seconds of the page starting to load. Anything over 4 seconds is considered poor. Slow server response, render-blocking resources, and unoptimized images are the usual culprits. INP measures interactivity. It tracks the delay between a user interaction (click, tap, keypress) and the browser's visual response. Good is under 200ms, poor is over 500ms. Heavy JavaScript execution during interactions tanks this metric. We see this most often on sites with bloated page builders or excessive third-party scripts. CLS measures visual stability. It quantifies how much visible content shifts unexpectedly during load. A score under 0.1 is good, over 0.25 is poor. Images without dimensions, ads that inject dynamically, and web fonts causing layout reflow are common causes. We fix this by reserving space for every element before it loads. Core Web Vitals matter because they directly affect rankings, though the impact is modest compared to relevance and authority. Google uses field data from real Chrome users (Chrome User Experience Report) to score your site, averaged over 28 days. You need 75% of page loads to hit the good threshold to pass. Most Ottawa SEO clients see ranking lifts of 2–8 positions after fixing critical CWV issues, more if they were previously flagged in Search Console. The business impact shows up faster in conversion rates than rankings because users genuinely prefer fast, stable pages.