How Fast Websites Increase Leads (With Real Numbers)
The relationship between page speed and conversion rate is one of the most studied in digital marketing — and it's stronger than most owners realize. We break down the data, the mechanism, and the practical fixes that actually move the number.
The data: what every 100ms costs you
Amazon famously found every 100ms of latency cost them 1% in sales. Walmart saw 2% conversion lift for every second improved. Across the local service businesses we work with, the average lift from cutting LCP from 4s to under 2s is 30–60% in form completions.
Why fast sites convert better
Speed reduces cognitive friction. A fast site feels professional and trustworthy. A slow site feels broken — and broken signals 'low quality,' which the visitor extends to your product or service.
What actually makes a site fast
Image optimization (WebP/AVIF, lazy loading, correct sizing), font subsetting, deferring third-party scripts, server-level caching, and modern frameworks that ship less JavaScript. Most sites can hit Lighthouse 90+ on mobile with a focused two-week sprint.
How to audit your own site
Run PageSpeed Insights, look at the field data (Chrome UX Report) more than the lab data, and prioritize LCP and INP. If LCP is over 2.5s on mobile, you're losing leads — full stop.
Want results like this for your business?