Why Your Website Is Slow, and How to Check It in 60 Seconds

A website is slow if its main content takes longer than 2.5 seconds to appear, or if it takes more than 200 milliseconds to react to a tap or click. Those are Google’s own published thresholds — Largest Contentful Paint (LCP) and Interaction to Next Paint (INP). To check yours: open pagespeed.web.dev, paste in your URL, and read the mobile score. It’s free, needs no account, and takes about a minute.

What “slow” actually means

Google groups site speed into three measurements, called Core Web Vitals:

LCP (Largest Contentful Paint) — how long until the biggest visible thing on the page (usually a hero image or headline) actually renders. “Good” is 2.5 seconds or under.
INP (Interaction to Next Paint) — how long the page takes to respond after someone taps a button or link. “Good” is 200 milliseconds or under.
CLS (Cumulative Layout Shift) — how much the page jumps around while loading (an image popping in and shoving the text down, for example). “Good” is a score of 0.1 or under.

Google uses these same numbers as a ranking signal, and PageSpeed Insights reports all three for free.

The 60-second check

Go to pagespeed.web.dev.
Paste in your homepage URL and run it.
Read the Mobile tab first — most visitors are on a phone, and mobile scores are almost always worse than desktop.
Look at the overall score (0–100) and the three Core Web Vitals numbers above it.

If the score is in the red, or your LCP is over 2.5 seconds, the rest of this guide explains why.

What usually causes it

In order of how often this actually shows up on a small business site:

Unoptimized images. A phone photo straight off a camera can be 4–8MB; a properly compressed hero image is closer to 100–200KB. This is the single most common cause of a slow LCP.
Render-blocking scripts. Chat widgets, multiple analytics tools, and ad trackers all load JavaScript before the page can finish painting — each one adds real, measurable delay.
Web fonts loaded without care. A font file that blocks rendering until it downloads makes text (or the whole page) invisible for longer than it needs to be.
Page builders and heavy themes. A WordPress site with a dozen active plugins, or a page built entirely in a drag-and-drop builder, ships far more code than the page actually needs — and most of it runs before a visitor sees anything.
No caching or CDN. Every visitor’s browser re-downloading the same unchanged files, served from one physical server far from them, adds delay that has nothing to do with the page’s design.

What “fast enough” looks like in practice

Every site BAD builds is gated on a Lighthouse score of at least 90 for Performance, Accessibility, Best Practices, and SEO before it ships — checked automatically, not eyeballed. That standard applies to everything in the work index, not just the flagship projects.

If your own number came back well under that, that’s a fixable problem, not a fact of life for your business.