In 2025, Google’s SEO algorithm is more user-centric than ever. While traditional on-page SEO elements like keywords, meta descriptions, and internal linking remain important, search engines now prioritise how users experience a page. This shift puts a spotlight on Core Web Vitals—a set of performance-based metrics—and broader UX signals, such as mobile responsiveness, layout stability, and engagement behaviour.
- 1. What Are Core Web Vitals?
- 2. Why Core Web Vitals Matter for SEO
- 3. Beyond Web Vitals: Behavioural UX Signals
- 4. How to Measure Core Web Vitals
- 5. Optimising for Largest Contentful Paint (LCP)
- 6. Improving Interaction to Next Paint (INP)
- 7. Reducing Cumulative Layout Shift (CLS)
- 8. Mobile UX: A Must-Have in 2025
- 9. Aligning UX with E-E-A-T Principles
- 10. Good UX = Better SEO Metrics
- 11. Case Example: UX Improvements in Action
- 12. Common UX Mistakes That Hurt SEO
- References
This article explores the role of Core Web Vitals and UX signals in SEO, their impact on ranking, and actionable strategies to improve both.
1. What Are Core Web Vitals?
Core Web Vitals are performance metrics defined by Google that assess key aspects of user experience:
- Largest Contentful Paint (LCP): Measures loading speed. Ideal is under 2.5 seconds.
- Interaction to Next Paint (INP): Replaces FID in 2024 to measure interactivity. Ideal is under 200 ms.
- Cumulative Layout Shift (CLS): Measures visual stability. Ideal is under 0.1.
These metrics form the foundation of Google’s Page Experience signals, which influence rankings alongside other on-page SEO practices (Google Developers, 2024a).
2. Why Core Web Vitals Matter for SEO
Though Core Web Vitals are not primary ranking factors, they help differentiate between equally relevant pages (Moz, 2024). Google confirmed that when content quality is similar, UX performance can influence rankings.
Websites that meet the recommended Core Web Vitals thresholds tend to:
- Appear higher in mobile search
- Reduce bounce rates
- Improve dwell time
- Convert visitors more effectively
In a study by Portent (2023), websites with fast loading speeds had a 20% higher organic visibility compared to slower pages.
3. Beyond Web Vitals: Behavioural UX Signals
Google also considers indirect user behaviour signals to determine relevance and satisfaction:
- Bounce rate: High rates may indicate that content or layout is poor.
- Time on page: Longer durations signal content engagement.
- Pages per session: Shows if users explore deeper content.
- Dwell time: Time spent before returning to the search result.
Although not officially confirmed as ranking signals, these metrics correlate with high-performing content and affect how search engines interpret page quality (Search Engine Journal, 2024).
4. How to Measure Core Web Vitals
Google provides multiple tools to test and monitor Core Web Vitals:
- PageSpeed Insights: Evaluates lab and field performance.
- Lighthouse: Audits pages for SEO and UX.
- Chrome UX Report (CrUX): Collects real user performance data.
- Web Vitals Extension: Chrome tool for real-time testing.
Tip: Prioritise CrUX data, as it reflects real-world user experiences across devices and locations (Google Developers, 2024b).
5. Optimising for Largest Contentful Paint (LCP)
LCP evaluates how fast the main visible content (like hero text or images) loads.
Common causes of poor LCP:
- Slow server response
- Large image files
- Render-blocking CSS/JS
Solutions:
- Use Content Delivery Networks (CDNs).
- Compress images via tools like TinyPNG.
- Minify CSS and JavaScript.
- Preload fonts and important assets.
6. Improving Interaction to Next Paint (INP)
INP measures how fast a page responds to a user’s first interaction, replacing FID as the new standard in March 2024.
Causes of poor INP:
- JavaScript execution delays
- Long main thread tasks
- Unoptimised third-party scripts
Optimisation tips:
- Defer non-critical JavaScript.
- Use web workers to offload tasks.
- Break up long tasks into smaller ones (Google Developers, 2024c).
7. Reducing Cumulative Layout Shift (CLS)
CLS evaluates unexpected layout shifts during page load, which is especially problematic on mobile.
Causes of high CLS:
- Images or ads loading without size dimensions
- Dynamic content (e.g., banners) pushing other elements down
- Late-loading fonts
Solutions:
- Always define image/video dimensions.
- Reserve space for injected content.
- Use font-display: swap for web fonts.
8. Mobile UX: A Must-Have in 2025
With mobile traffic accounting for over 65% of global web use (Statista, 2024), mobile-first indexing is standard.
Mobile optimisation checklist:
- Responsive design (media queries and fluid grids)
- Tap-friendly buttons and spacing
- Font sizes that are legible without zoom
- Fast loading via mobile networks (3G or 4G)
Use the Mobile-Friendly Test to check readiness.
9. Aligning UX with E-E-A-T Principles
Google’s E-E-A-T framework (Experience, Expertise, Authoritativeness, Trustworthiness) is critical in 2025.
How UX contributes to E-E-A-T:
- Experience: Clean design and fast loading show effort and credibility.
- Expertise: Pages that are easy to navigate signal thoughtful structure.
- Authoritativeness: Professional layouts and error-free pages build authority.
- Trustworthiness: Secure HTTPS, no pop-ups, and consistent branding increase user confidence.
UX is not just a ranking factor—it’s a trust factor (Google Search Central, 2024).
10. Good UX = Better SEO Metrics
UX-focused design improves behavioural SEO signals:
| UX Element | SEO Metric Affected |
| Fast load speed | Bounce rate, time on page |
| Stable layout | Dwell time, return visits |
| Mobile optimisation | Mobile rankings, CTR |
| Structured content | Readability, snippet eligibility |
(Semrush, 2024)
11. Case Example: UX Improvements in Action
A health blog improved UX by:
- Compressing images (WebP format)
- Implementing lazy loading
- Switching to a mobile-first layout
Before:
- LCP: 3.8s
- INP: 310 ms
- CLS: 0.19
- Organic traffic: 12,000/month
After (3 months):
- LCP: 1.8s
- INP: 110 ms
- CLS: 0.05
- Organic traffic: 17,500/month
Source: Internal benchmark via Google Analytics and PageSpeed Insights, 2024
12. Common UX Mistakes That Hurt SEO
- Relying only on desktop testing
- Overusing animations and large media files
- Not prioritising first interaction speed
- Neglecting layout stability on dynamic content
- Ignoring mobile usability
Solution: Regular audits using Lighthouse and Core Web Vitals tools.
Note
Google’s commitment to rewarding user-focused websites continues to grow. In 2025, Core Web Vitals and UX signals are not optional—they are foundational.
To rank well:
- Monitor and improve LCP, INP, and CLS.
- Design for mobile-first interaction.
- Align UX with E-E-A-T expectations.
- Use SEO tools to combine technical performance with engaging design.
In short, great content must be delivered with great experience. The websites that combine both will dominate SERPs.
More Read
References
Google Developers. (2024a). Core Web Vitals. https://web.dev/vitals/
Google Developers. (2024b). Chrome UX Report (CrUX). https://developer.chrome.com/docs/crux/
Google Developers. (2024c). Interaction to Next Paint (INP). https://web.dev/inp/
Google Search Central. (2024). Page Experience Report. https://developers.google.com/search/docs/appearance/page-experience
Moz. (2024). How Core Web Vitals Impact SEO. https://moz.com/blog/core-web-vitals-seo
Portent. (2023). Page Speed and SEO Study. https://www.portent.com/blog/seo/page-speed-study.htm
Search Engine Journal. (2024). UX Signals and SEO: How They Interact. https://www.searchenginejournal.com
Semrush. (2024). UX, Page Speed, and SEO Correlation Report. https://www.semrush.com/blog
Statista. (2024). Global Mobile Internet Traffic Share. https://www.statista.com/statistics/277125/
