In 2024, Google published updated research showing that mobile sites loading in under 2.5 seconds had conversion rates 2x higher than sites loading in 4+ seconds. By 2026, people had become even less patient with slow pages as fast websites and AI interfaces made near-instant responses feel normal.
“A one-second improvement in load time increases conversions by an average of 27%. For most SMEs, that translates to tens of thousands in recovered revenue.”
What the Data Shows
Across our client base, we measured the correlation between Core Web Vitals scores and lead generation. Businesses in the "good" range for all three metrics generated 3-4x more enquiries per thousand visitors than those in the "needs improvement" range. The relationship was exponential, with small improvements at the top end producing larger returns.
The Three Metrics That Matter
- Largest Contentful Paint (LCP): how quickly the main content appears. Target: under 2.5 seconds.
- Interaction to Next Paint (INP): how responsive the page feels when you click. Target: under 200ms.
- Cumulative Layout Shift (CLS): how much the page moves while loading. Target: under 0.1.
Many performance problems come from the way the site is built. Image optimisation, suitable hosting and removing unused JavaScript can often move a site from "poor" to "good" in one focused sprint.
Written by Mihai Diaconita
Founder & CEO
Building conversion-focused websites since 2009. Passionate about data-driven design and helping businesses turn their websites into growth engines.
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