An E-shop That Converts: Speed, UX and Core Web Vitals

Most e-shop owners invest in ads to bring visitors, yet let the store itself leak half that traffic before it ever reaches checkout. The reality is that an e-shop is a conversion machine: every extra second of load time, every needless checkout step and every unclear button costs you orders.

In this article we look at the three levers that, in our experience, make the biggest difference to conversion rate: speed, user experience and Google's Core Web Vitals.

Industry studies consistently show that each extra second of LCP (Largest Contentful Paint) can cut conversion rate by 5–10%. On an e-shop with €200,000 in annual revenue, that is tens of thousands of euros quietly evaporating.

The usual culprits are uncompressed product images, sliders loading above the header, and a pile of external scripts (chat, popups, analytics). Moving to WebP/AVIF formats, lazy-loading below the fold, and stripping unnecessary third-party scripts usually drops LCP under 2.5 seconds with no redesign.

Three metrics define the experience today: LCP (how fast the main content appears), INP (Interaction to Next Paint — how fast the page responds to clicks and typing) and CLS (how much the layout shifts as it loads). INP officially replaced FID in March 2024, so older reports no longer suffice.

Check real field data through Search Console and CrUX, not just Lighthouse lab scores. The target: LCP under 2.5s, INP under 200ms and CLS under 0.1 for 75% of real visits.

The average cart abandonment rate hovers around 70%. Price is not always to blame — often it is forced account creation, hidden shipping costs revealed at the last step, and forms with dozens of fields.

The practices that work: guest checkout, showing the full cost early, one step per screen on mobile, address autofill, and visible trust signals (payment logos, return policy) next to the pay button. Every field you remove from the form is one fewer reason for the customer to leave.

Set up funnel analytics in GA4 with events for view_item, add_to_cart, begin_checkout and purchase, so you can see exactly where audiences drop off. A typical weak link: the add_to_cart-to-begin_checkout ratio collapses on mobile — a sign the mini-cart or first checkout step has an issue.

Combine quantitative data with session recordings and heatmaps to see the "why". Improvements grounded in data, not in taste, are the ones that hold over time.

An e-shop that converts is not about flashy design but about removing friction. Fast loading, clean Core Web Vitals and a frictionless checkout return far more than any new ad campaign run on top of a slow store.