Core Web Vitals
Core Web Vitals are a set of standardized metrics. Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift, that quantify real-user page experience.
Also known as: cwv · web-vitals
Why it matters
Slow or janky pages lose users before they read. CWV pass rates correlate with better engagement and are a technical hygiene signal search systems can use alongside relevance.
How it works
Browsers record field data aggregated in CrUX; lab tools like Lighthouse simulate conditions. LCP targets the main content paint, INP captures responsiveness, CLS measures unexpected layout shifts. Fixes target fonts, images, JS hydration, and layout reservations.
Common mistakes
- Optimizing lab scores on staging that does not match production CDN behavior.
- Lazy-loading the LCP hero image.
- Injecting banners without reserved space, destroying CLS.
- Shipping huge client bundles on content-heavy marketing pages.
Best practices
- Prioritize field CrUX data for money URLs over lab vanity.
- Preload LCP images and critical fonts.
- Reserve space for ads, embeds, and dynamic UI.
- Measure after auth and cookie banners, they affect real users.
Learn Domains perspective
A landing page with strong rankings but a six-second load time still loses trials. Learn Domains tracks Core Web Vitals as a Digital Asset Score driver and puts your slowest money pages in the Mission Brief: fix LCP on `/pricing` before optimizing blog footers.
FAQ
- Are Core Web Vitals a direct ranking factor?
- Google uses page experience signals among many factors; treat CWV as user and technical hygiene.
- LCP or CLS first?
- Fix whichever fails worst on your top landing URLs, often LCP on content pages, CLS on ad-heavy templates.
- Does the Learn Domains app affect my site CWV?
- No, it analyzes your property; it does not inject scripts into your site.
Next steps
- 1Pull CrUX or PSI report for top three landing URLs.
- 2Fix the failing metric on highest-traffic page first.
- 3Re-measure after deploy with field data.
Knowledge graph
Parent terms
Related concepts
index-coverage · digital-asset-score