Why Is My Website So Slow? Core Web Vitals Explained

A slow website quietly costs you money — visitors leave before the page loads, and Google ranks you lower for it. If your site feels sluggish, the culprit usually shows up in three metrics Google calls Core Web Vitals. Here's what they mean in plain English and what you can do about them.

What Core Web Vitals actually measure

• LCP (Largest Contentful Paint) — how long until the main content appears. Aim for under 2.5 seconds. This is "how fast does it feel?"
• INP (Interaction to Next Paint) — how quickly the page responds when someone taps or clicks. Aim for under 200ms. This is "does it feel laggy?"
• CLS (Cumulative Layout Shift) — how much the page jumps around as it loads. Aim for under 0.1. This is "why did the button move just as I tapped it?"

Why it matters for your business

Two reasons, both tied to revenue:

• Conversions. Every second of delay measurably reduces the number of people who buy, sign up, or contact you. Speed is a conversion lever, not a technical nicety.
• Search rankings. Core Web Vitals are a confirmed Google ranking factor. A faster site is easier to rank — and your competitors are paying attention.

What's usually making it slow

• Unoptimized images — huge files served at full resolution.
• Too much JavaScript — heavy scripts and third-party tags blocking the page.
• Slow hosting or no caching — the server takes too long to respond.
• Render-blocking resources — fonts and stylesheets that delay the first paint.
• Layout shifts — images and ads without reserved space, shoving content around.

How to fix it

The first step is measurement. Run your site through Google PageSpeed Insights to see your real-world scores and a prioritized list of issues. From there, the common wins are image optimization, reducing and deferring JavaScript, proper caching, and a modern, well-architected front end.

Some of this you can tackle in-house. But if your site is built on a slow foundation, patching symptoms only goes so far — performance has to be designed in.

If your site is dragging and you want a clear diagnosis, see how we approach performance optimization or get a free speed audit. We'll tell you exactly what's slowing you down and what it'll take to fix.