Core Web Vitals
Core Web Vitals are Google's three most important metrics for the user experience on your online store: loading speed (LCP), interactivity (INP) and visual stability (CLS). They are an official Google ranking factor and directly influence your search positions.
What are Core Web Vitals?
Core Web Vitals (CWV) is a set of three metrics Google uses to measure the technical user experience on a website. They were launched in 2020 and have been an official ranking factor since 2021. Poor Core Web Vitals can drag down your Google positions, while good scores provide a competitive advantage.
The three Core Web Vitals
LCP (Largest Contentful Paint)
Measures loading speed - specifically how long it takes for the largest visible content item (typically a hero image or large block of text) to fully render.
- Good: Under 2.5 seconds
- Needs improvement: 2.5-4.0 seconds
- Bad: Over 4.0 seconds
INP (Interaction to Next Paint)
Replaced FID (First Input Delay) in March 2024. Measures responsiveness - how quickly the page visually responds to user interactions such as clicks, taps and keyboard input throughout the visit.
- Good: Under 200 milliseconds
- Needs improvement: 200-500 milliseconds
- Bad: Over 500 milliseconds
CLS (Cumulative Layout Shift)
Measures visual stability - how much the page content jumps around unexpectedly during loading.
- Good: Below 0.1
- Needs improvement: 0.1-0.25
- Bad: Over 0.25
Why is CWV important for your online store?
- Google ranking: CWV is an official ranking factor. Two pages with the same content and relevance - the one with better CWV ranks higher.
- Conversion rate: Fast, stable pages convert better. Google has documented that a 100ms improvement in LCP can increase conversions by up to 2%.
- User experience: Slow pages, unresponsive buttons and jumping layouts frustrate customers and send them to competitors.
- Bounce rate: 53% of mobile visitors leave a page that takes more than 3 seconds to load.
How to improve CWV
LCP optimization
- Optimize images (WebP format, correct size, lazy loading for under-fold images)
- Minimize CSS and JavaScript that block rendering
- Use CDN to deliver static files faster
- Preload the most important image (hero image)
INP optimization
- Minimize JavaScript execution and avoid long tasks (>50ms)
- Defer or lazy-load third-party scripts (chat, analytics, pixels)
- Use requestAnimationFrame for visual updates
CLS optimization
- Always set dimensions (width/height) on images and videos
- Reserve space for dynamic content (banners, ads)
- Use font display: swap with preload for web fonts
Measurement tools
- Google Search Console: The Core Web Vitals report shows data for your entire site based on real user data.
- PageSpeed Insights: Detailed analysis of individual pages with concrete suggestions for improvement.
- Chrome DevTools (Lighthouse): Lab-based performance audit with detailed metrics.
- Web Vitals Extension: Chrome extension that displays CWV in real-time.
We know online marketing in Shoporama
We've been working with online marketing ourselves for decades. As the only shop system in the country, we have spoken multiple times at conferences such as Marketingcamp, SEOday, Shopcamp, Digital Marketing, E-commerce Manager, Ecommerce Day, Web Analytics Wednesday and many more.