How landing page load speed affects conversion

Landing page load speed decides who sees your offer

Every landing page has a queue. Someone taps an ad, the browser starts fetching, and the visitor waits. On a phone on patchy 4G, a heavy page can sit blank for four or five seconds. A good share of visitors leave before the headline paints. They never see the offer and they never reach the button. Your copy could be excellent and it would still not matter. With paid traffic you pay for that click either way. So landing page load speed decides how many people get to judge everything else you built.

The three numbers worth tracking

Google publishes three thresholds and they work well as targets. Largest Contentful Paint should land under 2.5 seconds. This is usually your hero image or your headline finishing its paint. Interaction to Next Paint should stay under 200 milliseconds, so taps feel instant. Cumulative Layout Shift should stay under 0.1, so the layout holds still while someone reads. Google grades these at the 75th percentile of real visits and splits mobile from desktop, so check both. Field data lags by weeks, so a lab test confirms a fix today.

What actually makes a page slow

The same offenders show up in almost every site we audit. A hero video autoplays and ships megabytes before anyone scrolls. Screenshots get exported at 3000 pixels wide and dropped into a 600 pixel slot. Four font weights load where two would do, and each one holds text back from painting. Then come the bolt-ons: a chat widget, a heatmap recorder, two ad pixels and an A/B testing script that blocks rendering while it picks a variant. Each one felt free at the time. Nobody tracks the running total.

Where to start this week

Start with the hero, because it is usually your LCP element. Serve a compressed WebP or AVIF, size it for the viewport, and do not lazy load it. Swap the autoplay video for a still image and a play button. Reserve height for images, embeds and banners so the page holds its shape. Then open the network tab, sort by size, and delete every third-party script nobody has checked in three months. Re-test on a real device over throttled mobile data. Most pages get faster when you take things away.