Core Web Vitals:
Three Scores. One Ranking Signal.

Google's 'Good' thresholds are: LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1. Pages that fall in the 'Needs Improvement' range are LCP between 2.5–4 seconds, INP between 200–500ms, and CLS between 0.1–0.25. Anything beyond those ranges is classified as 'Poor.' Google evaluates these at the 75th percentile of field data — meaning 75% of your real users need to experience Good scores for the page to pass.

Yes. Core Web Vitals remain an active Google ranking signal as part of the Page Experience update. Google has consistently confirmed their role in rankings, and they were expanded in 2024 with INP replacing FID as the interactivity metric. Beyond SEO, they measure real user experience — slow LCP, high CLS, and sluggish INP directly correlate with higher bounce rates and lower conversions. Sites with passing Core Web Vitals consistently outperform failing competitors in competitive SERPs where content quality is comparable.

For LCP: preload the largest above-the-fold image, improve server response time (TTFB), and eliminate render-blocking resources. For INP: minimize JavaScript execution time, break up long tasks, and defer non-critical scripts. For CLS: set explicit width and height attributes on all images and videos, avoid inserting content above existing content after load, and use font-display: swap to prevent layout shifts from font loading. In Next.js, the Image component with priority=true handles LCP image preloading automatically.

LCP (Largest Contentful Paint) measures how long it takes for the largest visible element on the page — typically a hero image or heading — to fully load. It's Google's primary measure of perceived load speed. CLS (Cumulative Layout Shift) measures visual stability: how much content unexpectedly shifts position during page load. A high CLS score means users are clicking the wrong thing because the page moved under them — a direct UX problem Google penalizes in rankings.

Poor LCP is most commonly caused by large unoptimized images, slow server response times, render-blocking JavaScript, and no resource preloading. Poor INP is typically caused by heavy JavaScript execution on the main thread, third-party scripts (chat widgets, analytics, ads), and unoptimized event handlers. Poor CLS is caused by images and embeds without defined dimensions, late-loading fonts that shift text, and dynamically injected banners or ads above existing content.

Yes — CLS is one of the three Core Web Vitals that Google uses as a ranking signal. A CLS score above 0.1 puts a page in the 'Needs Improvement' category; above 0.25 is 'Poor.' Beyond the direct ranking impact, CLS creates a frustrating user experience that increases bounce rate and reduces conversions. Common fixes include adding explicit width and height to all images, reserving space for ads and embeds before they load, and avoiding late-injected content that pushes down page elements.