Core Web Vitals are three specific performance metrics Google uses to measure how fast and stable your pages feel to real users. They're part of your ranking signals, though not the dominant ones—content quality and relevance still matter more, but when two pages are otherwise equal, the faster one wins. The three metrics are Largest Contentful Paint (LCP), which measures how long it takes for your main content to load—Google wants under 2.5 seconds. First Input Delay (FID) tracks how quickly your page responds when someone clicks or taps something—target under 100 milliseconds. Cumulative Layout Shift (CLS) measures visual stability, penalizing pages where buttons or text jump around as images or ads load—aim for under 0.1. Note that FID is being replaced by Interaction to Next Paint (INP) in March 2024, which measures overall responsiveness instead of just the first interaction. Google grades you based on field data from real Chrome users visiting your site, collected through the Chrome User Experience Report. You can check your scores in Google Search Console under the Core Web Vitals report or use PageSpeed Insights for individual URLs. The tricky part is that your scores depend on your actual visitor devices and connections—a site might pass on desktop but fail on mobile if most of your traffic comes from older phones or slower networks. Common fixes we implement at Ottawa SEO include lazy-loading images, deferring non-critical JavaScript, setting explicit width and height attributes on images and ads to prevent layout shifts, and upgrading to faster hosting. For WordPress sites, we often see 30-40% improvements just from switching to a lightweight theme and limiting plugins. Canadian e-commerce sites tend to struggle most with CLS because of third-party review widgets and dynamic pricing scripts. Core Web Vitals won't save a page with thin content, but ignoring them means leaving rankings on the table, especially in competitive niches where everyone's content is decent. Fix the obvious stuff first—oversized images, render-blocking CSS—before obsessing over decimal-point improvements.