Core Web Vitals optimization targets three metrics: Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS). Google uses these as ranking signals, so hitting the "good" thresholds—LCP under 2.5 seconds, FID under 100 milliseconds, CLS under 0.1—matters for both user experience and search visibility. For LCP, identify your largest visible element (usually a hero image or heading block) using Chrome DevTools or PageSpeed Insights. Serve images in next-gen formats like WebP or AVIF at appropriate dimensions, implement lazy loading for below-the-fold content, and use a CDN to reduce server response time. Preload critical assets with <link rel="preload"> and eliminate render-blocking CSS or JS in the critical path. If you're on shared hosting in Canada, upgrading to a VPS or managed WordPress host typically shaves 300-800ms off LCP. FID measures interactivity. Minimize JavaScript execution time by code-splitting, deferring non-essential scripts, and removing unused third-party tags. Google Tag Manager stacks are common culprits—we've seen sites drop from 180ms to 60ms FID by auditing and removing redundant tracking pixels. Consider moving analytics to server-side or using Cloudflare Zaraz to offload client-side weight. CLS happens when elements shift during load. Reserve space for images and embeds with explicit width/height attributes, avoid inserting content above existing elements (like cookie banners pushing text down), and use CSS aspect-ratio for responsive media. Fonts cause layout shifts too—use font-display: swap cautiously and preload critical font files. At Ottawa SEO, we run monthly Core Web Vitals audits across our portfolio using real field data from Chrome User Experience Report, not just lab tests. Lab scores guide fixes, but field data (what real users experience) determines rankings. A site passing in PageSpeed Insights but failing in Search Console's CrUX report won't get the ranking benefit. Focus on the 75th percentile of real user visits, especially on mobile and slower Canadian networks outside urban cores.