Google doesn’t just care about your content anymore. Since 2021, they’ve been measuring how your website actually performs for real users — and using that data to influence your rankings.
These measurements are called Core Web Vitals, and they’ve become essential reading for any Irish business that depends on search traffic.
What Are Core Web Vitals?
Core Web Vitals are three specific measurements that Google considers essential indicators of user experience:
Largest Contentful Paint (LCP)
What it measures: How quickly the main content loads Good score: Under 2.5 seconds Needs improvement: 2.5 to 4 seconds Poor: Over 4 seconds
LCP measures when the largest visible element (usually an image or heading) finishes loading. It’s the closest approximation to when visitors feel the page is “ready.”
Interaction to Next Paint (INP)
What it measures: How quickly the page responds to user interactions Good score: Under 200 milliseconds Needs improvement: 200 to 500 milliseconds Poor: Over 500 milliseconds
INP replaced First Input Delay (FID) in March 2024. It measures responsiveness throughout the entire page visit, not just the first interaction. When you click a button or tap a link, how long until something happens?
Cumulative Layout Shift (CLS)
What it measures: Visual stability — how much elements move around Good score: Under 0.1 Needs improvement: 0.1 to 0.25 Poor: Over 0.25
CLS captures that frustrating experience when you’re about to click a button and suddenly the page shifts, causing you to click something else. Usually caused by images without dimensions or late-loading ads.
Why Core Web Vitals Matter for Irish Businesses
They’re a Google Ranking Factor
Google confirmed Core Web Vitals as a ranking factor in 2021. While content quality and relevance remain more important, all else being equal, sites with better Core Web Vitals will rank higher.
For competitive Irish keywords, this can be the difference between page one and page two.
They Affect User Behaviour
The metrics Google chose aren’t arbitrary. Slow loading, poor responsiveness, and layout shifts all correlate with:
- Higher bounce rates
- Lower time on site
- Reduced conversions
- More abandoned carts (for e-commerce)
Improving Core Web Vitals improves user experience, which improves business results — regardless of SEO impact.
They’re Measurable and Objective
Unlike subjective claims about “fast” or “slow,” Core Web Vitals provide concrete numbers. You can measure progress, compare against competitors, and demonstrate improvement over time.
How to Check Your Core Web Vitals
PageSpeed Insights
The primary tool for Core Web Vitals analysis:
- Visit pagespeed.web.dev
- Enter your URL
- Review both Lab Data and Field Data
Lab Data: Simulated tests showing potential issues Field Data: Real user measurements from Chrome (most important for rankings)
If your site doesn’t have Field Data, it means Chrome doesn’t have enough real visitor data yet. Focus on Lab Data and the Field Data will develop over time.
Google Search Console
For sites with enough traffic:
- Log into Search Console
- Navigate to Experience > Core Web Vitals
- Review Mobile and Desktop reports
- Click issues for affected pages
Search Console shows which URLs fail Core Web Vitals and groups them by common issues.
Chrome DevTools
For detailed technical analysis:
- Open Chrome DevTools (F12)
- Go to the Performance tab
- Click Record and reload the page
- Analyse the waterfall and timings
This helps identify exactly what’s causing problems.
Improving LCP (Largest Contentful Paint)
Poor LCP usually stems from slow server response, large images, or render-blocking resources.
Optimise Your Server Response
Target: TTFB (Time to First Byte) under 600ms
- Use server-level caching (LiteSpeed, Nginx FastCGI)
- Enable page caching with a quality plugin
- Implement object caching with Redis
- Choose a host with fast infrastructure
SparkHost sites typically achieve 100-200ms TTFB thanks to LiteSpeed servers and proper caching.
Optimise Your LCP Element
The LCP element is usually your hero image or largest heading. Focus optimisation there:
For images:
- Compress aggressively (under 200KB for hero images)
- Use WebP format
- Add preload hints for above-the-fold images
- Avoid lazy loading the LCP image
For text:
- Ensure fonts load quickly
- Use font-display: swap to show text immediately
- Consider system font stacks for critical text
Remove Render-Blocking Resources
CSS and JavaScript in the head can delay rendering:
- Defer non-critical JavaScript
- Inline critical CSS
- Load non-essential CSS asynchronously
- Remove unused CSS and JavaScript
Improving INP (Interaction to Next Paint)
INP problems typically come from JavaScript that blocks the main thread, preventing the browser from responding to user input.
Reduce JavaScript Execution Time
- Audit plugins for JavaScript bloat
- Remove unused plugins entirely
- Defer or async load non-critical scripts
- Consider removing heavy page builders
Break Up Long Tasks
JavaScript tasks over 50ms block user interactions. Modern approaches:
- Use requestIdleCallback for non-urgent work
- Chunk large operations into smaller pieces
- Avoid synchronous operations where possible
Common WordPress Culprits
- Heavy page builders (Elementor Pro, Divi)
- Chat widgets and pop-up plugins
- Analytics and tracking scripts
- Social sharing buttons
- Carousel and slider plugins
Audit your plugins. Ask: “Is this worth the performance cost?”
Improving CLS (Cumulative Layout Shift)
CLS happens when elements change size or position after initially rendering.
Always Set Image Dimensions
Every image should have width and height attributes:
<img src="photo.jpg" width="800" height="600" alt="Description">WordPress adds these automatically for images in the Media Library, but check:
- Theme-added images
- Manually coded images
- Third-party plugin images
Reserve Space for Ads and Embeds
Ads that load late and push content down are CLS killers:
- Reserve minimum space for ad containers
- Use skeleton loaders for dynamic content
- Avoid inserting content above existing content
Avoid Web Font Flash
When custom fonts load late, text resizes:
- Preload critical fonts
- Use font-display: swap or optional
- Ensure font file sizes are optimised
- Consider variable fonts
Check for Plugin Culprits
Common CLS offenders:
- Cookie consent banners that push content
- Newsletter pop-ups
- Chat widgets
- Related posts that load dynamically
Either configure these to appear without shifting, or consider alternatives.
WordPress-Specific Optimisations
Choose Theme and Plugins Carefully
Your choice of theme has enormous impact on Core Web Vitals:
Good: GeneratePress, Astra, Kadence, Blocksy — lightweight, performance-focused
Problematic: Avada, Divi, BeTheme — powerful but heavy
Page builders add significant JavaScript. If you’re serious about performance, choose your theme carefully and consider Gutenberg with a lightweight theme.
Optimisation Plugins
Perfmatters: Excellent for removing bloat, deferring scripts WP Rocket: All-in-one with good CWV features Flying Scripts: Delays JavaScript until user interaction Asset CleanUp: Removes unused CSS/JS per page
Host Selection Matters
Your hosting directly impacts LCP through server response time. Shared hosting with slow servers makes good Core Web Vitals nearly impossible.
Managed WordPress hosting with:
- LiteSpeed or modern Nginx configuration
- SSD/NVMe storage
- Adequate resources
- Server-level caching
- CDN integration
SparkHost is specifically optimised for Core Web Vitals. Our speed optimisation services help sites achieve green scores without extensive configuration.
The Reality Check
Perfect Core Web Vitals scores aren’t always achievable — or necessary.
What matters:
- Being in the “Good” threshold for real users
- Better scores than direct competitors
- Genuine improvements to user experience
What doesn’t matter:
- Perfect 100/100 scores
- Lab data from specific test conditions
- Obsessing over every decimal point
Many successful sites have imperfect Core Web Vitals but still rank well because their content is excellent. Focus on getting to “Good” thresholds and then move on.
Creating an Action Plan
- Assess current state — Run PageSpeed Insights on key pages
- Identify priorities — Which metrics are failing? Which pages matter most?
- Address infrastructure first — Hosting, caching, CDN
- Optimise images — Often the biggest single improvement
- Audit plugins — Remove the heavy, unnecessary ones
- Refine JavaScript — Defer, async, or eliminate
- Fix CLS issues — Image dimensions, font loading, dynamic content
- Test and iterate — Measure, improve, repeat
The SparkHost Difference
Our hosting infrastructure is designed for Core Web Vitals performance:
- LiteSpeed servers — Faster than Apache or Nginx
- Built-in caching — No plugin configuration needed
- Cloudflare CDN — Global delivery, reduced latency
- Redis object caching — Fast database operations
- Optimised PHP — Latest versions, optimal configuration
Sites migrated to SparkHost often see Core Web Vitals improve from red/orange to green without any other changes.
Take Action Today
- Test your key pages at pagespeed.web.dev
- Note which Core Web Vitals are failing
- Start with the biggest issues first
- Measure improvements as you go
- Consider your hosting if server response is slow
Core Web Vitals aren’t just about Google rankings. They’re about giving your visitors a better experience. Get them right, and everyone wins.