Core Web Vitals passing thresholds are LCP (Largest Contentful Paint) under 2.5 seconds, FID (First Input Delay) under 100ms or INP (Interaction to Next Paint) under 200ms, and CLS (Cumulative Layout Shift) under 0.1. Google measures at the 75th percentile of real-world visits, so you need three-quarters of your users hitting these marks, not just lab tests. For LCP, the biggest wins come from optimizing your hero image or main content block. Use next-gen formats like WebP or AVIF, implement proper lazy loading on below-fold images, and serve images through a CDN. Preload critical resources and eliminate render-blocking CSS and JavaScript in the critical path. Server response time matters too—shared hosting environments over 600ms TTFB make sub-2.5s LCP nearly impossible without aggressive caching. INP replaced FID in March 2024 and measures all interactions, not just the first one. Reduce JavaScript execution time by code-splitting, deferring non-essential scripts, and avoiding massive third-party tag managers. WordPress sites running 15+ plugins often fail here. Consider moving analytics and chat widgets to load after user interaction. CLS failures come from images without width/height attributes, ads that push content down, or web fonts causing layout reflow. Reserve space for every dynamic element—embeds, banners, cookie notices. Use font-display: swap carefully and consider preloading critical fonts. Avoid injecting content above existing content after page load. At Ottawa SEO, we run monthly CrUX reports from Search Console and cross-reference with PageSpeed Insights. Lab scores (Lighthouse) are useful for diagnosis but don't determine passing—only real user data from the Chrome User Experience Report counts. For portfolio sites, we've seen LCP improvements from 4.2s to 1.8s just by switching from unoptimized PNGs to WebP and implementing Cloudflare caching. The tradeoff is development time versus traffic value—a 500-visit-per-month blog doesn't justify two weeks of optimization, but a lead-gen site pulling 50 conversions monthly does.