Core Web Vitals
Quick Definition
Core Web Vitals are a set of three metrics (LCP, INP, CLS) that Google uses to measure real-world user experience on web pages. They are a confirmed ranking factor that evaluates loading speed, interactivity, and visual stability.
Why It Matters
Core Web Vitals are a confirmed Google ranking factor. They measure real user experience, not just server metrics. Sites that pass Core Web Vitals have faster pages, better interactivity, and more stable layouts -- all of which reduce bounce rate and improve conversions.
Real-World Example
An e-commerce site with a 4-second LCP (Largest Contentful Paint) loses visitors before the main product image loads. After optimizing images and server response time to achieve a 1.5-second LCP, the site passes Core Web Vitals and sees improved rankings for product-related searches.
Signal Connection
Trust -- When your site loads fast, responds instantly to clicks, and does not shift around visually, users trust it more. Core Web Vitals are Google measuring whether your site delivers a trustworthy user experience.
Pro Tip
Run PageSpeed Insights (pagespeed.web.dev) on your homepage right now. It shows your Core Web Vitals scores with specific recommendations. Focus on fixing red metrics first -- they have the biggest impact.
Common Mistake
Students test their site only in Chrome DevTools on a fast computer and think they pass. Core Web Vitals uses real user data from the Chrome User Experience Report. Your lab scores can be perfect while real users on mobile networks experience slow performance.
Test Your Knowledge
What are the three Core Web Vitals metrics?
Show Answer
Answer: B. LCP (loading), INP (interactivity), CLS (visual stability)
The three Core Web Vitals are LCP (Largest Contentful Paint) for loading speed, INP (Interaction to Next Paint) for interactivity, and CLS (Cumulative Layout Shift) for visual stability.