How to Fix Core Web Vitals Issues: LCP, INP, CLS Explained

What Are Core Web Vitals?

Core Web Vitals are Google's set of real-world metrics that measure user experience on the web. Since 2022, they've been direct ranking factors. In 2026, they remain critical for both SEO and user retention.

The three metrics are:

• LCP (Largest Contentful Paint) — Loading performance
• INP (Interaction to Next Paint) — Interactivity
• CLS (Cumulative Layout Shift) — Visual stability

Fixing LCP (Target: Under 2.5s)

LCP measures how long the largest visible element takes to load. Common culprits and fixes:

1. Optimize Images

• Convert to WebP or AVIF format (40-80% smaller than JPEG)
• Use responsive images with srcset
• Lazy-load below-the-fold images
• Serve appropriately sized images for the viewport

2. Eliminate Render-Blocking Resources

• Defer non-critical CSS and JavaScript
• Inline critical CSS in the
• Use rel="preload" for hero images and fonts

3. Improve Server Response Time

• Use a CDN (Cloudflare, Vercel Edge, etc.)
• Enable HTTP/2 or HTTP/3
• Optimize database queries on the backend
• Implement caching strategies

4. Optimize Web Fonts

• Use font-display: swap
• Subset fonts to include only needed characters
• Preload critical fonts with rel="preload"

Fixing INP (Target: Under 200ms)

INP measures how quickly your page responds to user interactions. This replaced FID in 2024.

1. Break Up Long Tasks

• Split JavaScript execution into chunks under 50ms
• Use requestIdleCallback for non-urgent work
• Implement code splitting and lazy loading

2. Optimize Event Handlers

• Debounce scroll and resize handlers
• Avoid complex DOM manipulations in event callbacks
• Use passive event listeners where possible

3. Reduce Main Thread Work

• Minimize JavaScript bundle size
• Remove unused polyfills and legacy code
• Use Web Workers for heavy computations

Fixing CLS (Target: Under 0.1)

CLS measures unexpected layout shifts during page load.

1. Set Explicit Dimensions

• Always set width and height on images and videos
• Use aspect-ratio CSS property for responsive elements
• Reserve space for ads and embeds

2. Avoid Late-Loading Content

• Don't inject content above existing content after load
• Pre-allocate space for dynamic elements
• Use skeleton screens with fixed dimensions

3. Use Font Display Swap

• Prevent layout shifts from custom fonts
• Set font-display: optional for non-critical fonts

Tools to Measure Core Web Vitals

• Google PageSpeed Insights — Lab and field data
• Chrome User Experience Report (CrUX) — Real-user metrics
• Search Console Core Web Vitals report — URL-level issues
• AI SEO Copilot — Automated CWV analysis with fix recommendations

Test Your Core Web Vitals Now

Run a free Core Web Vitals analysis on any URL. Get a traffic-light score for all five metrics plus specific optimization steps.