Core Web Vitals and website speed: a simple guide for business owners

What Core Web Vitals are

Core Web Vitals are three measurements of how a page feels to a real visitor: how fast the main content loads, how quickly the page responds when you tap or click, and whether things jump around while it loads. Google publishes clear targets for each, and offers free tools to check them.

Google explains how they relate to search in its guide to Core Web Vitals and Google Search. They are one part of the technical basics in our technical SEO checklist.

The three metrics and their targets

These targets come from Google’s Web Vitals documentation, which says pages should meet them at the 75th percentile of page loads, measured separately for mobile and desktop. INP became a stable Core Web Vital in 2024 and replaced First Input Delay.

How to test your site

1. PageSpeed Insights. Enter a page address at PageSpeed Insights. It shows real-user data when available and a lab test with suggested fixes.
2. Search Console. The Core Web Vitals report groups your pages by status for mobile and desktop. See About Search Console to set it up.
3. Your own phone. Open key pages on a mid-range phone with mobile data. If it feels slow to you, it is slow to customers.

Lab tests and real-user data can differ, because real visitors use different devices and networks. Use the real-user data to judge, and the lab tests to diagnose.

Improving loading speed (LCP)

• Resize and compress images, and serve modern formats where your platform supports them.
• Make sure the main image or heading is not delayed by heavy scripts or slow servers.
• Use good hosting and caching so pages start loading quickly.
• Avoid loading large sliders and videos at the top of key pages.

Google’s guide to optimising LCP goes deeper.

Improving responsiveness (INP)

• Remove scripts and plugins you do not need, such as unused chat widgets, trackers and animation libraries.
• Delay non-essential scripts until after the page is usable.
• Keep pages simple where visitors must tap or type, such as forms and menus.

See Google’s guide to optimising INP.

Improving stability (CLS)

• Set width and height for images and video so the browser reserves space.
• Reserve space for ads, banners and cookie notices instead of pushing content down.
• Load fonts in a way that does not cause large text jumps.

See Google’s guide to optimising CLS.

What to fix first

1. Oversized images on your homepage and top landing pages.
2. Unused plugins, scripts and tracking tags.
3. Layout jumps on mobile, especially banners and popups.
4. Slow hosting, if the server is slow even for simple pages.

Fix problems on your most important pages first, especially pages that receive ad or search traffic. Our landing page guide explains why speed matters for enquiries.

What to expect

Better speed makes visitors happier and can reduce the number who leave before the page loads. It is part of page experience, but it does not replace helpful content, and Google does not promise ranking gains from any single change. Treat it as a way to keep visitors, and measure enquiries, not just scores.

Mistakes to avoid

• Chasing a perfect score at the cost of useful features.
• Testing only on a fast office connection and a new laptop.
• Adding more plugins to fix speed problems.
• Ignoring mobile.
• Fixing the homepage but leaving key service pages slow.

The bottom line

Know the three metrics, test with the free tools, fix the biggest problems first and re-check after each change. Fast, stable pages serve visitors and support everything else you do in marketing.

If you would like your site’s speed checked, our free growth audit includes a review of your key pages, or see our SEO, AEO and GEO service.