How to Check Core Web Vitals for Free: A Complete Step-by-Step Guide [2026]

Your website could be losing Google rankings right now, not because of bad content or missing keywords, but because a page loads 200 milliseconds too slowly on a mid-range Android phone.

Core Web Vitals are Google’s official page experience metrics. They measure how fast your pages load, how quickly they respond to user input, and how stable your layout is as it loads. Since Google made them a ranking signal in 2021, they have become one of the most concrete, measurable levers any website owner can pull to improve search performance.

In 2026, they matter for one additional reason most guides do not mention: Core Web Vitals are also an AEO and GEO signal. Google AI Overviews and other answer engines deprioritise slow, unstable pages when selecting content to cite. A page that fails Core Web Vitals is less likely to appear in AI answers regardless of how well its content is written.

This guide tells you exactly what Core Web Vitals are, how to check them for free in under two minutes, what your scores actually mean, and how to fix every metric that is failing.

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What are Core Web Vitals?

Core Web Vitals are three specific page experience metrics that Google uses as ranking signals: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS). Together they measure the loading speed, interactivity, and visual stability of a webpage from a real user’s perspective.

Google introduced Core Web Vitals in 2020 and made them a live ranking factor in June 2021. In March 2024, Interaction to Next Paint (INP) replaced First Input Delay (FID) as the interactivity metric after data showed INP was a more accurate measure of real-world responsiveness.

Each metric has a clear pass/fail threshold. Pages that hit “Good” on all three get a positive ranking signal. Pages in the “Needs Improvement” or “Poor” range receive no benefit and in competitive niches, that gap is enough to separate page one from page two.

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The three Core Web Vitals explained

What is LCP (Largest Contentful Paint)?

LCP measures how long it takes for the largest visible element on the page usually a hero image, heading, or video thumbnail to fully load from the user’s perspective.

Think of LCP as the moment the page feels “ready”. Not fully loaded in a technical sense, but loaded enough that the user can see the main content they came for.

LCP score	Rating
0 – 2.5 seconds	✅ Good
2.5 – 4.0 seconds	⚠️ Needs improvement
Over 4.0 seconds	❌ Poor

What causes a poor LCP score:

• Large, uncompressed hero images (the single most common cause)
• Slow server response times (TTFB above 600ms)
• Render-blocking JavaScript and CSS loaded before the main content
• No CDN serving assets from a single origin server far from the user

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What is INP (Interaction to Next Paint)?

INP measures the time between a user interacting with your page clicking a button, tapping a link, pressing a key and the browser visually responding to that interaction. It replaced FID in March 2024.

Where FID only measured the delay before the browser started responding, INP measures the full response time including the time to complete the visual update. It is a more complete picture of how responsive your site actually feels.

INP score	Rating
0 – 200 milliseconds	✅ Good
200 – 500 milliseconds	⚠️ Needs improvement
Over 500 milliseconds	❌ Poor

What causes a poor INP score:

• Heavy JavaScript executing on the main thread during interactions
• Third-party scripts (chat widgets, analytics, ad tags) blocking the browser
• Large DOM size pages with thousands of HTML elements respond slowly
• Long tasks (JavaScript tasks over 50ms) blocking the main thread

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What is CLS (Cumulative Layout Shift)?

CLS measures how much the visible content on your page unexpectedly moves around as it loads images popping in, ads shifting text, fonts swapping and reflowing the layout.

If you have ever tried to click a button and had the page shift just as your finger lands, causing you to tap something else that is a CLS event. It is one of the most frustrating user experiences on the web, and Google penalises it directly.

CLS score	Rating
0 – 0.1	✅ Good
0.1 – 0.25	⚠️ Needs improvement
Over 0.25	❌ Poor

What causes a poor CLS score:

• Images and videos without defined width and height attributes in HTML
• Ads or embeds without reserved space
• Web fonts loading late and causing text to reflow (FOUT means Flash of Unstyled Text)
• Dynamically injected content above existing content (cookie banners, notification bars)

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Why Core Web Vitals matter beyond rankings in 2026

Most guides stop at “they affect your Google ranking.” In 2026, there are two additional reasons they matter that are directly relevant to your traffic.

Core Web Vitals affect AEO – your chances of appearing in AI answers

Google AI Overviews select content to cite based on multiple signals, one of which is page experience. A page that fails Core Web Vitals signals to Google’s systems that it delivers a poor user experience. Even if the content is excellent and the FAQ schema is perfect, a Poor-rated CWV page is at a consistent disadvantage for AI citation selection.

Check your AEO score alongside your Core Web Vitals both need to be healthy for maximum AI visibility. Run a free AEO check →

Page experience is a trust signal for GEO

Generative Engine Optimization getting AI models like ChatGPT and Gemini to cite your brand unprompted depends heavily on whether your brand is perceived as authoritative and trustworthy. A slow, layout-shifting site undermines that trust signal. AI models learn from web data at scale. Sites that consistently deliver poor experiences are implicitly lower-authority sources.

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How to check your Core Web Vitals for free

There are four reliable ways to check Core Web Vitals for free. Here is when to use each one.

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Method 1: SEO Inspector Hub Core Web Vitals Checker (fastest – under 30 seconds)

Best for: Quick checks, client audits, agencies needing a branded report with CWV data included

SEO Inspector Hub’s free Core Web Vitals checker runs a full CWV audit on any URL and returns your LCP, INP, and CLS scores alongside 60+ other SEO signals all in one place. The results are exportable as a white label PDF report for client delivery.

How to use it:

1. Go to seoinspectorhub.com/core-web-vitals-checker/
2. Enter your URL no account required
3. Results appear in under 30 seconds: LCP, INP, CLS scores with pass/fail status
4. Scroll to see specific elements causing failures and recommended fixes
5. Export as a branded PDF if you need a client-ready report

This is the fastest route from “I don’t know my scores” to “I know exactly what to fix.”

Check your Core Web Vitals free →

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Method 2: Google PageSpeed Insights (most detailed lab data)

Best for: Developers who need granular diagnostic data and specific element-level recommendations

PageSpeed Insights (PSI) is Google’s own tool at pagespeed.web.dev. It provides both lab data (simulated test in a controlled environment) and field data (real-world measurements from Chrome users who visited your page, pulled from the Chrome User Experience Report).

How to use it:

1. Go to pagespeed.web.dev
2. Enter your URL and click Analyse
3. Switch between Mobile and Desktop tabs always check mobile first, as Google uses mobile-first indexing
4. Under “Diagnose performance issues”, find element-level details: which specific image is your LCP element, which scripts are causing long tasks, which elements are shifting your layout

Important: PSI lab data uses a simulated slow 4G connection on a mid-range device. Your scores will look worse than on your own desktop. This is intentional it reflects the median user experience, not the best-case scenario.

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Method 3: Google Search Console (real-world data for your whole site)

Best for: Site owners who want to see which pages are failing across their entire site, not just one URL at a time

Google Search Console’s Core Web Vitals report shows real-world CWV data from Chrome users, grouped by “Good”, “Needs Improvement”, and “Poor” across all pages Google has data for.

How to access it:

1. Log in to search.google.com/search-console
2. In the left sidebar, click Experience → Core Web Vitals
3. Click into the Mobile or Desktop report
4. Google groups failing pages by issue type e.g. “LCP issue: longer than 4s” so you can fix an entire category of pages at once rather than page by page

This is the only method that shows you real user data across your full site. The other tools test one URL at a time in a lab environment. Start here if you manage a site with more than 20 pages.

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Method 4: Chrome DevTools (for developers debugging specific issues)

Best for: Developers who need to reproduce and diagnose CWV failures in real time

Chrome DevTools provides live performance profiling in your browser no external tool needed.

How to use it:

1. Open Chrome, navigate to the page you want to test
2. Press F12 (or right-click → Inspect) to open DevTools
3. Click the Performance tab
4. Click the record button, interact with the page, then stop recording
5. Look for long tasks (red bars in the timeline) these are the main thread blocks causing poor INP
6. The Lighthouse tab inside DevTools runs the same analysis as PageSpeed Insights but on your local machine, useful for testing pages behind a login

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How to fix Core Web Vitals issues

Once you know which metrics are failing, here are the highest-impact fixes for each one.

Fixing LCP (page loads too slowly)

Fix 1: Compress and resize your hero image The hero image is the LCP element on most pages. Run it through Squoosh.app (free) and convert to WebP format. A 400KB hero image compressed to 60KB with no visible quality loss is the single most impactful LCP fix for most websites.

Fix 2: Add fetchpriority="high" to your LCP image This tells the browser to load the hero image before anything else. One line of HTML, significant LCP improvement:

html

<img src="hero.webp" fetchpriority="high" alt="your description here">

Fix 3: Use a CDN (Content Delivery Network) A CDN serves your assets from a server physically close to the user. Cloudflare’s free plan covers most small-to-medium sites and can cut TTFB (server response time) by 40–60%.

Fix 4: Eliminate render-blocking resources Scripts and stylesheets in your <head> that load before your content delay LCP. Add defer to non-critical scripts:

html

<script src="analytics.js" defer></script>

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Fixing INP (page feels unresponsive to clicks and taps)

Fix 1: Audit and remove unnecessary third-party scripts Chat widgets, marketing pixels, A/B testing scripts, and ad tags all compete for the main thread. Use PageSpeed Insights’ “Reduce JavaScript execution time” section to identify which third-party scripts are the worst offenders. Remove any you do not actively use.

Fix 2: Break up long JavaScript tasks Any JavaScript task over 50ms blocks the main thread and delays INP. If you manage your own JavaScript, use setTimeout or scheduler.yield() to break long tasks into smaller chunks. If you use a page builder (WordPress + Elementor, Webflow, etc.), update to the latest version most have shipped INP improvements in 2025–2026.

Fix 3: Use content-visibility: auto on off-screen content This CSS property tells the browser to skip rendering content that is not currently visible, freeing up main thread time for interactions:

css

.below-fold-section {
  content-visibility: auto;
}

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Fixing CLS (layout jumps around as it loads)

Fix 1: Add explicit width and height to every image This is the most common CLS cause and the easiest fix. Without dimensions, the browser does not know how much space to reserve while the image loads:

html

<!-- Wrong — causes layout shift -->
<img src="photo.jpg" alt="description">

<!-- Correct — reserves space before image loads -->
<img src="photo.jpg" width="800" height="450" alt="description">

Fix 2: Reserve space for ads and embeds Use a min-height CSS wrapper around ad slots and iframe embeds so the layout does not shift when they load:

css

.ad-slot {
  min-height: 250px;
}

Fix 3: Preload web fonts and use font-display: optional Late-loading fonts cause text to reflow as the font swaps. Preloading the font and setting font-display: optional prevents the reflow:

html

<link rel="preload" href="font.woff2" as="font" type="font/woff2" crossorigin>

css

@font-face {
  font-display: optional;
}

Fix 4: Stop inserting content above existing content dynamically Cookie banners, newsletter popups, and notification bars that push content down after the page loads are major CLS sources. Render them in a fixed position overlay or include them in the initial HTML rather than injecting them via JavaScript after load.

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Core Web Vitals quick-fix checklist

LCP fixes

• Hero image compressed to WebP and under 100KB
• fetchpriority="high" added to LCP image element
• CDN enabled (Cloudflare free plan covers most sites)
• Render-blocking scripts moved to defer or end of body

INP fixes

• Third-party scripts audited – unused ones removed
• Long JavaScript tasks broken up or eliminated
• Page builder / CMS updated to latest version
• content-visibility: auto applied to below-fold sections

CLS fixes

• Width and height attributes on every <img> tag
• Ad slots and iframes have reserved min-height
• Web fonts preloaded with font-display: optional
• Cookie banners and popups render in fixed position, not inline

After fixing – verify

• Re-run your Core Web Vitals check: seoinspectorhub.com/core-web-vitals-checker/
• Re-run PageSpeed Insights on mobile
• Submit fixed URLs in Google Search Console → URL Inspection → Request Indexing
• Check Search Console CWV report again in 28 days (Google’s field data takes time to update)

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Frequently Asked Questions

What are Core Web Vitals and why do they matter?

Core Web Vitals are three page experience metrics used by Google as ranking signals: LCP (loading speed), INP (interactivity), and CLS (visual stability). They matter because they directly affect your position in Google search results, your eligibility for Google AI Overview citations, and the overall experience visitors have on your site. Poor scores mean lower rankings and fewer citations in AI-powered search results.

How do I check Core Web Vitals for free?

You can check Core Web Vitals for free using four tools: SEO Inspector Hub’s free Core Web Vitals checker (fastest results in 30 seconds), Google PageSpeed Insights (most detailed diagnostic data), Google Search Console (real-world data across your full site), or Chrome DevTools (for developers debugging in real time). No paid tools are required.

What is a good Core Web Vitals score?

Good Core Web Vitals scores are: LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1. Pages that hit “Good” on all three metrics receive a positive ranking signal from Google. Pages in the “Needs Improvement” or “Poor” range receive no ranking benefit and may be disadvantaged in AI citation selection.

How long does it take to fix Core Web Vitals?

Simple fixes image compression, adding width/height attributes to images, removing unused third-party scripts — can be implemented in a few hours and show measurable improvement immediately in lab tests. Real-world field data in Google Search Console takes 28 days to update, so allow four weeks after making fixes before judging the impact on Search Console scores.

Do Core Web Vitals affect AEO and AI search results?

Yes. Google AI Overviews use page experience signals including Core Web Vitals when selecting content to cite. A page that fails Core Web Vitals is at a consistent disadvantage for AI citation selection, even if its content quality is high. Fixing Core Web Vitals improves both traditional ranking and your chances of appearing in AI-powered search results. Check your full AEO readiness at SEO Inspector Hub.

Does fixing Core Web Vitals guarantee a ranking improvement?

No, Core Web Vitals are one of many ranking signals. Fixing them removes a ranking disadvantage rather than guaranteeing a jump in position. However, for pages that are failing (Poor rating), moving to Good can have a meaningful impact in competitive niches where competitors are already passing. They are also the most technically controllable ranking signal — unlike backlinks or domain authority, you can fix them directly on your own site.

What replaced FID in Core Web Vitals?

Interaction to Next Paint (INP) replaced First Input Delay (FID) as the Core Web Vitals interactivity metric in March 2024. FID only measured the delay before the browser started responding to an interaction. INP measures the full response time — including the time to complete the visual update making it a more accurate reflection of how responsive a page actually feels to real users.

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Conclusion

Core Web Vitals are not a one-time fix. Page speed degrades as you add new features, plugins, third-party scripts, and heavier images over time. The sites that maintain Good scores treat CWV as a regular audit item not a project to complete once and forget.

The process is straightforward: check your scores, identify which metric is failing, apply the relevant fixes from this guide, verify the improvement, and recheck in 28 days.

Start right now your scores take less than 30 seconds to check, and you may find that a single image compression fix is all that stands between you and a Good rating on LCP.

Check your Core Web Vitals free →

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Related guides and tools: AEO Checker · GEO Checker · Free SEO Audit Tool · White Label SEO Reports