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How to Improve Your LCP Score (Core Web Vitals Guide 2026)

LCP (Largest Contentful Paint) is one of Google's three Core Web Vitals — and it's a direct ranking signal. A score above 2.5 seconds hurts your search rankings. Here's how to fix it.

May 18, 2026·8 min read·AuditAI Team

Since 2021, Google has used Core Web Vitals as a ranking signal in its Page Experience update. LCP, CLS, and INP are the three metrics — and LCP is typically the hardest to pass. In 2026, more than 50% of websites still fail Google's LCP threshold.

The first step is knowing your score. AuditAI lets you check your LCP score, CLS score, and INP score for free — no login required — and gives you AI-generated fixes for every failing metric.

What Are Core Web Vitals?

Core Web Vitals are three user-experience metrics Google uses to measure real-world page performance:

LCP — Largest Contentful Paint

How long it takes for the largest visible element (usually a hero image or heading) to fully load.

✓ Good: Under 2.5 seconds✗ Poor: Over 4.0 seconds

CLS — Cumulative Layout Shift

How much the page layout jumps around while loading (unexpected shifts that make users click the wrong thing).

✓ Good: Under 0.1✗ Poor: Over 0.25

INP — Interaction to Next Paint

How long it takes the page to visually respond after a user clicks, taps, or types. Replaced FID in March 2024.

✓ Good: Under 200ms✗ Poor: Over 500ms

How Does Google Use Core Web Vitals for Rankings?

Google's Page Experience signal combines Core Web Vitals with HTTPS status and mobile-friendliness. Pages that pass all three Core Web Vitals thresholds receive a ranking boost compared to equivalent pages that fail.

It's not a dramatic boost — content quality still dominates — but when two pages are closely matched on quality and relevance, Core Web Vitals can be the tiebreaker. For competitive niches, passing LCP, CLS, and INP is no longer optional.

Why Is My Core Web Vitals Score Failing?

LCP failures have six common root causes. Here's each one with its impact and fix:

Slow server response time (TTFB)

High impact

Fix: Use a CDN, upgrade hosting, enable server-side caching. Every 100ms of TTFB adds roughly 100ms to LCP.

Render-blocking JavaScript and CSS

High impact

Fix: Add defer or async to non-critical JS. Inline critical CSS. Use <link rel="preload"> for your hero image.

Slow resource load time (large hero image)

High impact

Fix: Convert images to WebP or AVIF. Use srcset for responsive images. Add loading="eager" and fetchpriority="high" to your LCP image.

Client-side rendering (React/Vue SPAs)

High impact

Fix: Switch to SSR or SSG. The LCP element can't be painted until the JavaScript loads and runs on client-rendered pages.

No preload for LCP resource

Medium impact

Fix: Add <link rel="preload" as="image" href="/hero.webp" fetchpriority="high"> in your <head>.

Unoptimised web fonts

Medium impact

Fix: Use font-display: swap. Preload your primary font. Self-host fonts instead of loading from Google Fonts.

How to Improve Your CLS Score

CLS failures almost always come from elements that load without reserved space. Common fixes:

Always set width and height attributes on all <img> tags
Reserve space for ads, embeds, and iframes with explicit dimensions
Avoid inserting DOM content above existing content (banners, cookie notices)
Use font-display: swap or preload fonts to prevent layout shift from font swaps
Animate only transform and opacity — not properties that affect layout like height or top

How to Improve Your INP Score

INP measures responsiveness. A slow INP usually means your main thread is blocked by long JavaScript tasks:

Break up long JavaScript tasks using setTimeout or scheduler.yield()
Defer non-critical third-party scripts (chat widgets, analytics, ad scripts)
Reduce event handler complexity — avoid synchronous data fetching inside click handlers
Minimise DOM size — large DOMs (over 1,500 nodes) significantly slow interaction response
Use a web worker for heavy computation so it doesn't block the main thread

How to Check Your LCP, CLS, and INP Scores Free

Run a free website audit at auditai.fyi— no login required. AuditAI measures your LCP score, CLS score, and INP score against Google's thresholds and provides AI-generated suggestions for each failing metric. You can also check your security headers, SEO, and GDPR compliance in the same scan.

Check Your Core Web Vitals Free

AuditAI checks your LCP, CLS, and INP scores — plus SEO, security headers, and GDPR/CCPA/DPDP compliance — in a single free website audit. No login required. AI-generated fixes included.

Check Core Web Vitals Free →

→ What Are Core Web Vitals? Complete Guide → How to Rank Higher on Google in 2026 → Technical SEO Audit Checklist 2026 → What Is a Website Audit? Complete Guide

What Are Core Web Vitals?

Core Web Vitals are three user-experience metrics Google uses to measure real-world page performance:

LCP — Largest Contentful Paint

How long it takes for the largest visible element (usually a hero image or heading) to fully load.

✓ Good: Under 2.5 seconds✗ Poor: Over 4.0 seconds

CLS — Cumulative Layout Shift

How much the page layout jumps around while loading (unexpected shifts that make users click the wrong thing).

✓ Good: Under 0.1✗ Poor: Over 0.25

INP — Interaction to Next Paint

How long it takes the page to visually respond after a user clicks, taps, or types. Replaced FID in March 2024.

✓ Good: Under 200ms✗ Poor: Over 500ms

How Does Google Use Core Web Vitals for Rankings?

Why Is My Core Web Vitals Score Failing?

LCP failures have six common root causes. Here's each one with its impact and fix:

Slow server response time (TTFB)

High impact

Fix: Use a CDN, upgrade hosting, enable server-side caching. Every 100ms of TTFB adds roughly 100ms to LCP.

Render-blocking JavaScript and CSS

High impact

Fix: Add defer or async to non-critical JS. Inline critical CSS. Use <link rel="preload"> for your hero image.

Slow resource load time (large hero image)

High impact

Fix: Convert images to WebP or AVIF. Use srcset for responsive images. Add loading="eager" and fetchpriority="high" to your LCP image.

Client-side rendering (React/Vue SPAs)

High impact

Fix: Switch to SSR or SSG. The LCP element can't be painted until the JavaScript loads and runs on client-rendered pages.

No preload for LCP resource

Medium impact

Fix: Add <link rel="preload" as="image" href="/hero.webp" fetchpriority="high"> in your <head>.

Unoptimised web fonts

Medium impact

Fix: Use font-display: swap. Preload your primary font. Self-host fonts instead of loading from Google Fonts.

How to Improve Your CLS Score

CLS failures almost always come from elements that load without reserved space. Common fixes:

Always set width and height attributes on all <img> tags

Reserve space for ads, embeds, and iframes with explicit dimensions

Avoid inserting DOM content above existing content (banners, cookie notices)

Use font-display: swap or preload fonts to prevent layout shift from font swaps

Animate only transform and opacity — not properties that affect layout like height or top

How to Improve Your INP Score

INP measures responsiveness. A slow INP usually means your main thread is blocked by long JavaScript tasks:

Break up long JavaScript tasks using setTimeout or scheduler.yield()

Defer non-critical third-party scripts (chat widgets, analytics, ad scripts)

Reduce event handler complexity — avoid synchronous data fetching inside click handlers

Minimise DOM size — large DOMs (over 1,500 nodes) significantly slow interaction response

Use a web worker for heavy computation so it doesn't block the main thread

How to Check Your LCP, CLS, and INP Scores Free

Check Your Core Web Vitals Free

AuditAI checks your LCP, CLS, and INP scores — plus SEO, security headers, and GDPR/CCPA/DPDP compliance — in a single free website audit. No login required. AI-generated fixes included.

Check Core Web Vitals Free →