Is your website fast on phones? Core Web Vitals in plain English

Most visitors to a small business website arrive on a phone, often on mobile data. If the page is slow or jumpy, they leave and message someone else. Google created Core Web Vitals to measure exactly that experience.

The three measures

LCP: Largest Contentful Paint

How long until the biggest thing on the first screen, usually the main photo or headline, has loaded. Google's target: within 2.5 seconds.

INP: Interaction to Next Paint

How quickly the page responds when someone taps a button, opens a menu or types in a form. Google's target: 200 milliseconds or less.

CLS: Cumulative Layout Shift

How much the page jumps while it loads. You have seen it: you go to tap "Call" and a banner pushes the button down. Google's target: 0.1 or less.

Google says a page passes when it meets all three targets for at least 75% of visits, measured separately on mobile and desktop.

How to check your own site

1. Open PageSpeed Insights or my free page speed check.
2. Paste your website address and run the test.
3. Look at the Mobile tab first.
4. If Google has enough real visitor data, it shows the three Core Web Vitals at the top. Below that is a lab score from a test run, which is useful for spotting problems.

Small sites often do not have enough real visitor data yet. That is normal. Use the lab results as a guide.

Common fixes that make a real difference

• Huge photos. A photo straight off a phone can be several megabytes. Resized and saved in a modern format like WebP, it can be a small fraction of that and look the same on screen.
• Too many plugins and scripts. Every chat widget, slider and tracking tag adds work for the phone. Keep only the ones that earn their place.
• No space reserved for images. If the page does not know how big an image will be, the text jumps when it loads. Setting width and height fixes most layout shift.
• Fonts that block the page. Load only the font weights you use.
• Cheap, slow hosting. A good host with a global network serves pages from close to the visitor, which matters when customers are in Jamaica and abroad.

Why it matters for your business

A fast site is not about chasing a perfect score. It is about the customer on a bus in Spanish Town with two bars of signal who wants your prices and your WhatsApp button now. Every site I build is tested on phones before launch, and speed work is included.

Sources

• Web Vitals, web.dev by Google
• PageSpeed Insights, Google