Definition

Core web vitals are Google signals that measure the user experience of a page. They are official ranking factors and rely on three main metrics:

• LCP (largest contentful paint): time to render the largest visible element. Target: under 2.5 seconds.
• INP (interaction to next paint): responsiveness to interactions. Target: under 200 ms (replaced FID in March 2024).
• CLS (cumulative layout shift): visual stability of the page. Target: under 0.1.

Why it matters

Beyond SEO, core web vitals have a direct impact on conversion. A fast and stable page keeps visitors engaged. For a corporate or SaaS site, it is also a credibility signal for B2B prospects.

How to improve them

• Optimize images (WebP, lazy loading, explicit dimensions)
• Reduce blocking JavaScript and defer non-critical scripts
• Use a CDN and proper caching
• Track over time with PageSpeed Insights, Search Console and mobile indexing