Why Your Website Is Slow (and How to Fix It): A Core Web Vitals Guide

On mobile, patience is short. A slow site loses leads before it has even shown its offer, and Google takes page experience into account. Speed isn't a technical detail: it's a condition for selling.

Core Web Vitals in plain English

• LCP (Largest Contentful Paint): how long the main element (often the top image or headline) takes to appear.
• INP (Interaction to Next Paint): how quickly the page responds to taps and clicks.
• CLS (Cumulative Layout Shift): visual stability, meaning elements that jump around while loading.

You can measure them for free with PageSpeed Insights and track them in Search Console under "Core Web Vitals".

The most common causes

Oversized images

Photos uploaded straight from a camera or phone, at huge resolutions and in the wrong format. The number-one cause. Fix: resize, compress, use modern formats (WebP, AVIF) and lazy-load offscreen images.

Too many plugins and scripts

On WordPress, each plugin can add files to every page. Add chat widgets, ad trackers and social embeds, and the browser spends its time loading code nobody needs.

Underpowered hosting

A slow or overloaded server makes every page slow, however optimised. A high server response time (TTFB) shows up in PageSpeed Insights.

A heavy theme or page builder

Some all-in-one themes load dozens of features you never use. The resulting code is bulky and hard to optimise.

The action plan

1. Measure your key pages (home, services, product pages) on mobile.
2. Optimise images: the quickest win.
3. Remove unused plugins and scripts, defer the non-critical ones.
4. Enable caching and a CDN (for example Cloudflare).
5. If the server is still slow, upgrade or change hosting.
6. For demanding projects, consider a modern framework like Next.js, built for performance.

Fast by design

Our websites are built for performance from day one, and our managed services include ongoing speed monitoring.