15 min read
AIO Copilot Team
Technical SEO

How to Improve Core Web Vitals: Complete 2025 SEO Guide

Core Web Vitals are critical Google ranking factors that measure user experience. Learn how to optimize LCP, FID, and CLS to improve your search rankings and provide better user experiences.

What You'll Learn

Measure Core Web Vitals
Optimize LCP scores
Fix FID issues
Reduce CLS problems
Monitor improvements
Technical SEO boost

What are Core Web Vitals?

Core Web Vitals are a set of specific factors that Google considers important in a webpage's overall user experience. They consist of three key metrics that measure loading performance, interactivity, and visual stability. Optimizing these metrics is crucial for Google SGE performance and should be part of your technical SEO audit process.

LCP

Largest Contentful Paint

Loading Performance

<2.5s

FID

First Input Delay

Interactivity

<100ms

CLS

Cumulative Layout Shift

Visual Stability

<0.1

Step 1: How to Measure Core Web Vitals

Essential Tools for Measurement:

  • Google PageSpeed Insights: Free tool providing real-world data
  • Google Search Console: Core Web Vitals report for your site
  • Chrome DevTools: Live testing and debugging
  • Web Vitals Extension: Real-time monitoring while browsing

How to Use Google PageSpeed Insights:

  1. Visit pagespeed.web.dev
  2. Enter your website URL
  3. Wait for the analysis to complete
  4. Review your Core Web Vitals scores
  5. Check both mobile and desktop results

Step 2: How to Optimize Largest Contentful Paint (LCP)

LCP measures how long it takes for the largest visible element to load. A good LCP score is 2.5 seconds or less.

Optimize Server Response Time

  • Use a Content Delivery Network (CDN)
  • Optimize your hosting server
  • Implement server-side caching
  • Minimize server processing time

Optimize Images and Media

  • Use next-gen image formats (WebP, AVIF)
  • Implement proper image sizing and compression
  • Add lazy loading for below-the-fold images
  • Preload critical images

Remove Render-Blocking Resources

  • Minify CSS and JavaScript files
  • Remove unused CSS and JavaScript
  • Inline critical CSS
  • Defer non-critical JavaScript

Step 3: How to Fix First Input Delay (FID)

FID measures the time from when a user first interacts with your page to when the browser responds. Aim for less than 100 milliseconds.

Key Optimization Strategies:

  • Reduce JavaScript execution time: Break up long tasks into smaller chunks
  • Remove unused JavaScript: Audit and eliminate unnecessary code
  • Use code splitting: Load only necessary JavaScript for each page
  • Optimize third-party scripts: Lazy load non-critical widgets
  • Use web workers: Move heavy computations off the main thread

Step 4: How to Reduce Cumulative Layout Shift (CLS)

CLS measures visual stability by tracking unexpected layout shifts. A good CLS score is less than 0.1.

Common CLS Causes and Fixes:

Images without dimensions

Always include width and height attributes

Ads and embeds

Reserve space for dynamic content

Web fonts

Use font-display: swap and preload fonts

Advanced Optimization Techniques

Technical Implementation

  • Implement critical resource hints (preload, prefetch)
  • Use service workers for caching strategies
  • Optimize database queries
  • Enable gzip/brotli compression

Monitoring and Testing

  • Set up Core Web Vitals monitoring
  • Use Real User Monitoring (RUM)
  • Regular performance audits
  • Test on various devices and connections

Measuring Success and Next Steps

After implementing optimizations, monitor your progress using these methods:

Success Metrics:

75%

of pages should pass Core Web Vitals

+15%

average SEO ranking improvement

28 days

to see ranking impact

Need Help Optimizing Core Web Vitals?

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