How to measure speed, free and in one minute
Go to PageSpeed Insights (pagespeed.web.dev), paste your domain and look at the mobile tab, not desktop: Google ranks with the mobile version and that's where sites break.
The two numbers that matter: LCP (main content should appear in under 2.5 seconds) and CLS (the page shouldn't jump while loading; under 0.1).
Cause 1: unoptimized images
It's the most common cause and the cheapest to fix. On a single site I audited I found 40 of 55 images unoptimized: multi-MB camera photos where 80 KB would do.
The fix: modern formats (WebP or AVIF), dimensions matching the real on-screen size, and lazy loading for anything below the fold.
Cause 2: too many scripts and plugins
Every plugin, chat widget, pixel and slider adds weight and blocks loading. The most extreme case I measured: a site whose main content took 45.1 seconds to appear on mobile. After the rebuild, 1.7 seconds: 26 times faster.
List everything your site loads and ask what's earning its place. What isn't, goes.
Cause 3: hosting and architecture
An oversold shared host, no CDN or a heavy theme puts a floor under your load time that no image optimization can break. Sometimes rebuilding pays: a 2018 WordPress I migrated to a static site went from 7.9 to 0.6 seconds of LCP.
Why it matters (it's not just impatience)
According to Google's data, the probability of a visitor bouncing rises 32% when load time goes from 1 to 3 seconds. Speed is also a ranking signal: a slow site shows up less and converts less, at the same time.
Quick check
- 01Measure your domain on PageSpeed Insights, mobile tab
- 02Note your LCP: over 2.5 seconds means there's work to do
- 03Check the weight of your largest images
- 04List plugins and scripts: remove what you don't use
- 05Measure again after every change
Save this list and run it against your own site.