Website speed and Core Web Vitals, in plain language

Google's research puts it bluntly: as load time grows from one to three seconds, the chance a visitor bounces rises by a third. Every second your site spends loading is paid for in visitors who never saw it, and in ad money spent bringing them there.

Speed has an official scoreboard: Core Web Vitals, three numbers Google measures on your real visitors. They sound technical, but each one describes something a human feels. Here is what they mean and how to fix them, in plain language.

The three numbers, translated

• LCP, Largest Contentful Paint. How long until the main content shows. Under 2.5 seconds is good. This is the "is anything happening?" feeling.
• INP, Interaction to Next Paint. How fast the page reacts when someone taps or clicks. Under 200 milliseconds is good. This is the "did that button work?" feeling.
• CLS, Cumulative Layout Shift. How much the page jumps around while loading. Under 0.1 is good. This is the "I tapped the wrong thing because everything moved" feeling.

Green on all three means your site feels solid. Red means visitors feel friction on every visit, whether they could name it or not.

Where to look up your scores

Two free tools, two different truths. PageSpeed Insights tests any page on demand and lists what slows it down: that is your diagnosis. Search Console's Core Web Vitals report shows how your real visitors experienced the last 28 days: that is your verdict. Fix from the first, judge from the second, and expect the field numbers to lag your fixes by a few weeks.

Fix the images first

In almost every slow site we audit, images are the biggest weight. Three moves solve most of it: compress and convert to WebP, serve sizes that match the screen instead of 4,000-pixel originals, and lazy-load everything below the fold so the first screen wins the race. Give images fixed dimensions too; that alone removes most layout shift, because the page stops jumping when they arrive.

Then the script pile

Every plugin, app, chat widget and tracking pixel ships JavaScript that the phone must chew through before the page responds; this is what wrecks INP. The fix is subtraction. Audit what actually runs, remove what nobody uses, and load what remains after the content instead of before it. Themes and page builders stack up the same way: a rebuild on a cleaner base sometimes beats another round of patches, which is a call our redesign checklist helps you make.

Cheap wins: caching and hosting

Caching lets returning visitors skip the loading entirely, and a CDN serves your files from close by instead of across an ocean. Most platforms switch both on with a setting. Hosting is the floor under everything: if the server takes two seconds to answer, no optimisation above it can save you. Cheap hosting is the most expensive line item on many invoices.

What speed buys you

Rankings, partly: Core Web Vitals are one of Google's page experience signals, an edge between comparable pages rather than a trump card. The bigger prize is human. Fast pages hold visitors, and visitors who stay convert; slow pages feed the leaks we mapped in traffic without sales. If you pay for clicks, speed literally multiplies your ad budget, which is why every landing page we build starts with a speed budget.

The short version

Measure with PageSpeed Insights, verify in Search Console. Compress the images, cut the scripts, switch on caching, and refuse cheap hosting. Aim for green: 2.5 seconds, 200 milliseconds, 0.1 shift. Your visitors will not send a thank-you note; they will just stay, which is better.

Frequently asked questions