Core Web Vitals, explained for South Florida business owners

The three grades, in plain English

Core Web Vitals are Google's way of grading how your website feels to use. Not how pretty it looks. Not how clever the copy is. How it feels on a phone, on a real connection, for a real visitor.

Each grade has a published passing line. Pass or fail is based on the 75th percentile of real visits for each metric, measured separately for mobile and desktop.

• ▸LCP, Largest Contentful Paint: measures when the largest eligible image or text block visible on screen appears. Good is 2.5 seconds or less at the 75th percentile.
• ▸INP, Interaction to Next Paint: measures responsiveness to clicks, taps and keyboard interactions through the next paint. Good is 200 milliseconds or less at the 75th percentile.
• ▸CLS, Cumulative Layout Shift: measures unexpected layout shifts during a visit. Good is a score of 0.1 or less at the 75th percentile.

LCP: how fast your main content shows

LCP times the appearance of the largest eligible image or text block in the visible area. Until it appears, your visitor is staring at a blank or half finished page. That delay can make the page frustrating to use.

The usual culprits: oversized photos uploaded straight from a camera, sliders loading five images when one would do, slow hosting and fonts that hold up the text. We identify the LCP element and check what delays its appearance, then fix the actual bottleneck. We test on a throttled mobile connection because that is where a slow site shows its true colors.

INP: how fast your page reacts

INP measures the gap between an action and a response. A tap on your menu. A click on add to cart. Typing into your contact form. If the page sits there thinking before it reacts, that delay is INP. It applies on desktop too: a mouse click counts the same as a tap.

Heavy scripts can delay interactions. Chat widgets, sliders, popups, tracking codes and plugins stacked on plugins all fight to run at once. The fix is boring and effective: remove what you do not use, delay what can wait and clean up what is left. Your site does not need to do less for the customer. It needs to do less behind the scenes.

CLS: things that jump around

You are about to tap a link and the page shifts. Now you have tapped an ad, the wrong product or nothing at all. That jump is a layout shift. CLS scores unexpected shifts based on how much content moves and how far, using the worst cluster of shifts during the visit.

The causes: images without set dimensions, banners and popups that shove content down late, and custom fonts that swap in after the text already appeared. Fixing it means reserving space for every image and embed before it loads, and loading fonts so the text stays put. Small changes. Big difference in how solid your site feels.

Lab data vs. field data

There are two kinds of speed data, and they answer different questions. Field data comes from real visitors using Chrome. Google collects it in a rolling 28-day window and only reports it when a page has enough eligible visits. Lab data comes from a simulated test you can run anytime.

Here is the part that surprises owners: rebuilding at your existing web addresses can keep your older field data, while a brand new site may have none. A new site can wait longer or shorter than 28 days before enough visits stack up for a report. Meanwhile, a throttled lab test measures performance under controlled conditions. Run it before a fix and after, on the same terms, and you have a fair comparison.

How to check your site, and how we fix it

You can check your own site for free. Go to Google's PageSpeed Insights, paste in your address and read the mobile tab. If you have Search Console set up, the Core Web Vitals report shows which pages pass and which fail. Five minutes, no technical skill required.

When you want the failures fixed, that is our job. We work on WordPress, Shopify, WooCommerce and custom sites built by anyone. We work on a copy of your site first, test the fix on our throttled mobile setup, then ship to live. You see the result before your customers do.

We hold ourselves to the same test. The J.M. Field site used to show its main content at 10.8 seconds on an old WordPress build. After our rebuild, it shows at 1.2 seconds: same lab test, same throttled mobile connection. SoFlo Web Services is part of J.M. Field, a Fort Lauderdale company serving South Florida businesses since 1993.

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