Core Web Vitals for Business Owners: How to Check and Improve Them

Core Web Vitals are part of Google's page experience signals. They measure real user experience rather than technical scores in a lab. Google uses data from real Chrome users and judges a page as passing when at least 75% of visits meet the "good" threshold for each metric.

INP replaced an older metric, First Input Delay (FID), in March 2024. If an old report mentions FID, it is out of date.

• Visitors leave slow sites. A page that loads slowly or jumps as you try to tap a button is frustrating, especially on mobile data.
• Sales and enquiries depend on it. Checkout pages, booking forms and contact forms all need to respond quickly.
• Search visibility. Core Web Vitals are one of many ranking signals. Great content still matters most, but when competing pages are similar, a better experience can help.
• Paid traffic works harder. If you pay for clicks through Google Ads, a slow landing page wastes some of that spend.

Method 1: PageSpeed Insights (any single page)

1. Go to pagespeed.web.dev.
2. Enter the full address of a page, such as your home page or a key product or service page, and click Analyse.
3. Look first at the top section, "Discover what your real users are experiencing". This is field data from real Chrome users. It shows whether the page passes the Core Web Vitals assessment.
4. Switch between the Mobile and Desktop tabs. Mobile is usually weaker and matters more for most businesses.
5. Scroll down to the Diagnose performance issues section. This is lab data from Lighthouse, a simulated test. Use its suggestions to find causes, but judge success by the field data.

If your site has low traffic, you may see "no data" for real users. In that case, use the lab results as a guide.

Method 2: Google Search Console (whole site)

1. Sign in to Google Search Console and select your property. If you have not set it up, add and verify your domain first.
2. In the left menu, open Experience and then Core Web Vitals.
3. Open the Mobile report, then the Desktop report.
4. Click an issue, such as "LCP issue: longer than 2.5 s (mobile)", to see groups of affected URLs with similar problems.
5. After fixing an issue, click Validate fix. Google then monitors real user data over the following weeks.

Method 3: Chrome DevTools (for your developer)

In Chrome, right-click a page, choose Inspect and open the Performance panel. It shows live LCP, INP and CLS as you use the page and helps pinpoint which element or script is responsible.

Improving LCP (loading)

• Optimise the hero image. Resize it to the size it is displayed at, compress it and use a modern format such as WebP or AVIF.
• Do not lazy-load the main image. Lazy-loading is great for images further down, but the largest image above the fold should load straight away. Your developer can also give it a high fetch priority.
• Improve server response time. Use good hosting, page caching and a content delivery network (CDN).
• Reduce render-blocking files. Large CSS and JavaScript files in the page header delay what visitors see.

Improving INP (responsiveness)

• Cut unnecessary third-party scripts. Chat widgets, tracking tags, heatmaps and social embeds all compete for the browser's attention. Remove the ones you no longer use.
• Break up long tasks. Developers can split heavy JavaScript into smaller pieces so the page can respond between them.
• Load non-essential scripts later, after the page has become interactive.
• Review heavy plugins or apps, especially on WordPress and Shopify, where each one can add scripts to every page.

Improving CLS (stability)

• Set width and height on images and videos so the browser reserves space before they load.
• Reserve space for ads, banners and embeds. Cookie banners and promo bars that push content down are common causes.
• Handle web fonts carefully so text does not jump when the custom font arrives.
• Avoid inserting content above existing content unless the visitor asked for it.

Any platform can pass Core Web Vitals, but each has typical weak spots:

• WordPress: page builders, heavy themes and large numbers of plugins are common causes of slow LCP and poor INP. A lean theme and good caching help a lot. Our WordPress development team works on exactly these issues.
• Shopify: the platform is fast at its core, but each app can add scripts to every page. Remove apps you no longer use and check that uninstalled apps have not left code in your theme.
• Custom and headless sites: these can be very fast, but large JavaScript bundles can still hurt INP if they are not split and loaded carefully.

Whatever the platform, the biggest gains usually come from fewer scripts, smaller images and better hosting.

1. Check Search Console to see which page groups fail and on which device.
2. Start with your highest-value templates: home page, key service or product pages, and checkout or contact pages.
3. Fix the quick wins first: image sizes, unused plugins and scripts, missing image dimensions.
4. Then tackle deeper issues such as hosting, theme code and JavaScript.
5. Re-test in PageSpeed Insights and validate fixes in Search Console.
6. Recheck after every redesign, new plugin or new marketing tag.

• "A score of 100 in PageSpeed is what matters." The performance score is a lab estimate. Passing the field data assessment is what counts.
• "A speed plugin will fix everything." Caching plugins help, but they cannot fix an oversized theme or a dozen heavy scripts.
• "Desktop is fine, so we are fine." Most visitors to many business sites use mobile, which is usually slower.

We review sites against Core Web Vitals, explain what is slowing them down in plain terms and fix the causes, whether you run WordPress, Shopify or a custom build. Start with a website audit, or contact us to talk about your site.