Core Web Vitals guide for business websites

What Core Web Vitals are

Core Web Vitals are three measurements Google uses to describe how a page feels to real visitors. They're part of what Google calls page experience. Google's Core Web Vitals documentation sets out the current metrics and the thresholds for a "good" result:

• Largest Contentful Paint (LCP) measures loading. Good is 2.5 seconds or less.
• Interaction to Next Paint (INP) measures responsiveness when someone taps or clicks. Good is 200 milliseconds or less. INP replaced First Input Delay in March 2024.
• Cumulative Layout Shift (CLS) measures visual stability, meaning how much things jump around while loading. Good is 0.1 or less.

Google assesses these at the 75th percentile of real visits, so most of your visitors need a good experience, not just those on fast connections.

How much they matter for rankings

Be realistic. Google says it uses Core Web Vitals in its ranking systems, but that great page experience doesn't override having the most relevant, helpful content. A fast page with nothing useful on it won't outrank a slower page that answers the question properly.

The bigger reason to care is customers. A slow, jumpy page on a phone loses enquiries, regardless of where it ranks.

How to check your site

Search Console

The Core Web Vitals report in Search Console groups your pages by status using real-world data from Chrome users. Small sites sometimes don't have enough traffic for data to appear. That's normal.

PageSpeed Insights

PageSpeed Insights shows two kinds of data for a single page:

• Field data, from real Chrome users, if there's enough of it.
• Lab data, from a simulated test run there and then.

Field data is what Google uses. Lab data is useful for diagnosing problems but can swing from test to test. Don't panic over a single lab score.

Fixing slow loading (LCP)

The largest element is usually a hero image or a big heading. Common fixes:

• Resize and compress the hero image. A photo straight off a camera can be several megabytes. Serve it at the size it's displayed, in a modern format such as WebP or AVIF.
• Don't lazy-load the main image. Lazy loading helps images lower down the page, but delays the one people see first.
• Cut render-blocking files. Large CSS and JavaScript files loaded at the top hold everything up.
• Improve server response. Cheap shared hosting can be slow to respond. Caching or a better host often helps.
• Use a CDN if visitors come from far away or the host is slow. Many hosts include one.

Fixing slow responses (INP)

INP problems usually come from too much JavaScript running in the browser. On small business sites the usual culprits are:

• Page builders that load large scripts on every page.
• Chat widgets, pop-ups and review carousels.
• Several tracking and advertising tags.
• Sliders and animations.

Remove what you don't use. Load third-party tools only on pages that need them. If a widget is essential, ask the provider whether a lighter version exists.

Fixing layout shifts (CLS)

Things that jump while loading frustrate people and lead to mis-taps. Typical fixes:

• Set width and height on images and video so the browser reserves space.
• Reserve space for cookie banners, ads and embeds.
• Load web fonts in a way that doesn't cause text to reflow badly.
• Avoid inserting banners above existing content after the page has loaded.

A worked example

A wedding photographer's home page had a full-screen slideshow of six large images, a font loaded from three different sources, an Instagram feed and a chat bubble. On a phone over 4G, the first image took a long time to appear and the page shifted twice as the feed and chat loaded.

The fixes took an afternoon. The slideshow became a single compressed hero image with its size set. The Instagram feed moved lower down the page and loaded only when scrolled to. The chat widget was removed, since enquiries came through the contact form anyway. Fonts were cut to one family. The page felt noticeably quicker, and the photographer's work was still front and centre.

What not to obsess over

• A perfect 100 lab score. It's a diagnostic, not a goal.
• Pages nobody visits. Focus on templates and pages that bring in customers.
• Tiny differences. Moving LCP from 2.1 to 1.9 seconds is unlikely to change anything you'd notice.

Keep it fast over time

Speed tends to decay as sites gain plugins, tracking tags and bigger images. Make a habit of:

• Compressing every image before upload.
• Checking PageSpeed Insights after adding any new tool or plugin.
• Reviewing the Search Console report monthly.
• Removing plugins and scripts nobody uses.

The web.dev Core Web Vitals pages go deeper if you or your developer want the technical detail.