What Are Core Web Vitals?

Core Web Vitals are three specific metrics Google uses to measure your website's user experience:

1. Largest Contentful Paint (LCP) - How long until the main content loads. Target: under 2.5 seconds. 2. Interaction to Next Paint (INP) - How quickly your site responds when someone clicks or taps. Target: under 200 milliseconds. 3. Cumulative Layout Shift (CLS) - How much the page layout jumps around while loading. Target: under 0.1.

Why Should You Care?

Google confirmed Core Web Vitals are a ranking factor. Sites that pass all three metrics rank higher than those that don't, all other things being equal.

But more importantly: fast sites make more money. Amazon found that every 100ms of latency cost them 1% in sales. For a small business, that translates to real lost enquiries.

How to Check Your Score

1. Google PageSpeed Insights (pagespeed.web.dev) - Enter your URL and get instant results 2. Google Search Console - Core Web Vitals report shows your site-wide performance 3. Chrome DevTools - Lighthouse tab gives detailed technical metrics

The 5 Most Common Speed Killers

1. Unoptimised Images (LCP Impact: High)

The #1 cause of slow websites. A single 5MB hero image can add 3-4 seconds to your load time.

Fix: Convert to WebP format, compress to 80% quality, serve responsive sizes, and lazy-load images below the fold.

2. Too Many Plugins/Scripts (INP Impact: High)

Every plugin adds JavaScript that the browser must download and execute. 15 WordPress plugins can add 2-3 seconds to your load time.

Fix: Audit your plugins. Remove anything you're not actively using. Defer non-critical scripts.

3. No Browser Caching (LCP Impact: Medium)

Without caching, returning visitors download everything from scratch every time.

Fix: Set cache headers for static assets (images, CSS, fonts). Use a CDN like Cloudflare (free tier is sufficient for most sites).

4. Render-Blocking CSS/JS (LCP Impact: High)

CSS and JavaScript files that block the browser from rendering the page until they're fully loaded.

Fix: Inline critical CSS, defer non-critical CSS, and use async/defer attributes on script tags.

5. Layout Shifts from Ads/Embeds (CLS Impact: High)

Images, ads, and embedded content that load without defined dimensions cause the page to jump.

Fix: Always specify width and height on images and iframes. Reserve space for dynamic content.

The Quick Win Checklist

  • [ ] Run PageSpeed Insights on your homepage
  • [ ] Convert all images to WebP
  • [ ] Enable browser caching
  • [ ] Remove unused plugins
  • [ ] Add width/height to all images
  • [ ] Defer non-critical JavaScript
  • [ ] Use a CDN (Cloudflare free works)

Want us to speed up your website? Request a free performance audit - we'll tell you exactly what's slowing you down and how to fix it.