Core Web Vitals: The 2026 Guide to LCP, INP & CLS
Core Web Vitals measure loading speed, responsiveness, and visual stability. Learn the 2026 thresholds for LCP, INP, and CLS and how to improve them.
Core Web Vitals are Google’s user experience metrics for loading speed, interaction responsiveness, and visual stability. The three current metrics are Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS). Each has a threshold Google considers “good.”
Strong web design and development supports these metrics through lean assets and stable responsive layouts.
Core Web Vitals use real visitor data from the Chrome User Experience Report alongside lab testing. A page can look fast locally while field data exposes problems on slower devices or networks.
The Three Core Web Vitals Metrics
Each metric targets a different part of how a page feels to use, and all three need to pass for a page to be considered good overall.
- Largest Contentful Paint (LCP) measures loading performance, specifically how long it takes for the largest visible content element (usually a hero image or heading block) to render.
- Interaction to Next Paint (INP) measures responsiveness across user interactions during a page visit. INP replaced First Input Delay in March 2024 because FID measured only the first interaction.
- Cumulative Layout Shift (CLS) measures visual stability. It scores unexpected movement while a page loads, such as an image pushing text down.
Google’s own developer documentation is the definitive source for how these metrics are calculated and updated. See web.dev’s Core Web Vitals reference for the current thresholds and measurement methodology.
Core Web Vitals Thresholds
| Metric | What it measures | ”Good” threshold |
|---|---|---|
| Largest Contentful Paint (LCP) | Loading speed of the main visible content | 2.5 seconds or less |
| Interaction to Next Paint (INP) | Responsiveness across all page interactions | 200 milliseconds or less |
| Cumulative Layout Shift (CLS) | Visual stability during load | 0.1 or less |
A page needs to meet the “good” threshold for at least 75% of real visits, at both mobile and desktop levels, to be classified as passing overall.
Why Core Web Vitals Matter for SEO
Core Web Vitals help teams evaluate page experience alongside search relevance and content quality. They provide evidence for technical improvements that may also strengthen the page presented in the SERP.
Core Web Vitals also provide a standard way to monitor loading, responsiveness, and stability. Teams can use the same measurements instead of relying on anecdotal complaints.
Strong technical performance supports a trustworthy, well-built site. Speed itself is not an E-E-A-T factor.
Our view: Third-party scripts deserve an early review when Core Web Vitals fail. Tag managers, chat widgets, and ad tags can delay rendering or interaction even when the server responds quickly.
What does current evidence show about Core Web Vitals?
Google evaluates Core Web Vitals at the seventy-fifth percentile.
Good thresholds include 2.5 seconds for LCP, 200 milliseconds for INP, and 0.1 for CLS.
Source: web.dev Core Web Vitals guidance, accessed 2026.
What has AC learned from Core Web Vitals?
Our view: Core Web Vitals work is most useful when field data identifies a specific template and interaction. We pair that evidence with visual review because a faster page can still fail users through unstable layouts, hidden controls, or confusing content.
FAQs
- What are the three Core Web Vitals? Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS), measuring loading, interactivity, and visual stability.
- Did INP replace FID? Yes. Interaction to Next Paint replaced First Input Delay in March 2024. It captures delays across interactions throughout a page visit.
- What is a good LCP score? 2.5 seconds or less, measured at the 75th percentile of real user visits.
- Are Core Web Vitals a Google ranking factor? They are part of Google’s page experience signals. Search performance still depends on relevance, content quality, and many other systems.
- How do I check my Core Web Vitals scores? Use Google Search Console’s Core Web Vitals report, PageSpeed Insights, or the Chrome DevTools Lighthouse panel. These tools provide complementary field and lab data.
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