Why a slow website is costing you customers (and how to fix it)

A visitor decides whether to stay on your site before reading a single word. If the page takes too long to paint, they leave. They don't think it through — they close the tab. And most business owners never see it, because they test their own site from the office computer, cached and on a good connection.

The three numbers that matter

LCP (Largest Contentful Paint). How long the main element takes to appear, almost always the big hero image. Should be under 2.5 seconds.

INP (Interaction to Next Paint). How long the page takes to respond when someone taps a button. Under 200 milliseconds.

CLS (Cumulative Layout Shift). How much the content jumps around while loading. It's what makes you tap the wrong button. Under 0.1.

Google uses all three as ranking signals, but that's the smaller point: they're the difference between someone messaging you and someone leaving for the next result.

The five causes behind almost every slow site

Unoptimized images. A 4 MB photo uploaded straight off a phone. It's the number one cause and the easiest to fix: modern format, correct dimensions, lazy loading for anything below the fold.

Page builders with bloated output. Templates that load ten libraries to render three buttons. Code you don't use still gets downloaded.

Accumulated plugins. Each one adds requests, scripts and stylesheets. Many stay installed years after anyone stopped using them.

Badly loaded fonts. Five typefaces with every weight will block text from painting. Two well-configured families are plenty.

Cheap shared hosting. If the server takes a full second to respond, no amount of browser-side optimization saves you.

How it actually gets fixed

Measure first: PageSpeed Insights with field data, not lab data, and always on mobile. Then attack in order of impact, not order of ease.

In practice, when a site is built on layers of template and plugins, optimizing it costs more than rebuilding it. A hand-coded site starts in the green and stays there, because it never loads anything it doesn't need. That's the difference between patching and building it right the first time.