Core Web Vitals are a set of metrics designed to measure important parts of real-world page experience. The current metrics are Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift.
They matter because a slow, unresponsive, or unstable page can frustrate visitors and reduce conversions. They are also part of Google's broader page-experience systems, but they are not the only factor that determines rankings.
Largest Contentful Paint
Largest Contentful Paint, or LCP, measures how quickly the largest visible content element loads. On many pages this is the hero image, headline area, or large text block.
A good target is an LCP of 2.5 seconds or less for at least 75 percent of page visits.
Common LCP problems
- Large, uncompressed hero images
- Slow server response
- Render-blocking CSS or scripts
- Web fonts that delay visible text
- Important content loaded too late by JavaScript
Ways to improve LCP
- Compress and properly size images
- Use modern image formats where supported
- Preload the true hero image
- Improve hosting and caching
- Remove unnecessary apps and scripts
- Inline critical styles carefully
Interaction to Next Paint
Interaction to Next Paint, or INP, measures how quickly the page visually responds after a user interacts with it. It considers clicks, taps, and keyboard interactions across the visit.
A good target is 200 milliseconds or less.
Common INP problems
- Long JavaScript tasks
- Too many third-party scripts
- Heavy app widgets
- Complex page builders
- Large DOM structures
- Work that blocks the browser's main thread
Ways to improve INP
- Reduce unused JavaScript
- Break long tasks into smaller work
- Delay nonessential third-party code
- Simplify interactive components
- Provide immediate visual feedback after clicks
Cumulative Layout Shift
Cumulative Layout Shift, or CLS, measures unexpected movement of visible content while a page loads. A good target is 0.1 or less.
Common CLS problems
- Images without width and height dimensions
- Late-loading banners
- Font swaps that change text size
- Ads or embeds that create space after load
- Popups that push content rather than overlay it
Ways to improve CLS
- Reserve space for images, videos, and embeds
- Avoid inserting content above existing content
- Use stable font-loading strategies
- Test cookie banners and promotional bars
Field data versus lab data
Field data comes from real users and reflects devices, networks, and behavior in the market. Lab data comes from a controlled test and is useful for diagnosis. A page can score differently because the two data types answer different questions.
How Core Web Vitals fit into SEO
Strong content, relevance, crawlability, indexing, links, and intent remain essential. Core Web Vitals should be treated as part of a complete technical and user-experience strategy, not a substitute for it.
Use them alongside a technical SEO audit and the broader troubleshooting guide for websites that are not ranking.
Core Web Vitals and conversions
Performance work should be evaluated against business outcomes. Faster pages can improve experience, but conversions also depend on message clarity, offer strength, trust, forms, and follow-up. Review why websites get traffic but no leads.
Frequently asked questions
Does passing Core Web Vitals guarantee rankings?
No. It improves an important part of page experience but does not guarantee rankings.
Should every page have the same scores?
No. Templates, content, scripts, and traffic conditions differ. Prioritize high-traffic and high-conversion pages.
Can plugins fix everything?
Optimization tools can help, but app conflicts, theme architecture, hosting, and third-party code often require deeper work.
Request a free marketing audit to review website performance, technical SEO, and conversion barriers.