Google wants to send searchers to pages that load quickly and feel smooth to use. Core Web Vitals are the metrics Google uses to measure that experience. They are part of Google’s page experience signals, and they also affect how many visitors stay on your site long enough to become customers.
This guide explains each metric in plain English, how to test your website and the most effective fixes.
The three Core Web Vitals
Largest Contentful Paint (LCP)
LCP measures how long it takes for the main content, usually a hero image or headline, to appear. A good score is 2.5 seconds or less.
Interaction to Next Paint (INP)
INP measures how quickly the page responds when someone clicks, taps or types. A good score is 200 milliseconds or less. INP replaced First Input Delay in 2024.
Cumulative Layout Shift (CLS)
CLS measures how much the page jumps around while loading, for example when an image or banner pushes text down. A good score is 0.1 or less.
How to test your Core Web Vitals
- PageSpeed Insights: shows real user data and lab tests for any URL.
- Google Search Console: the Core Web Vitals report groups pages that need attention.
- Chrome DevTools Lighthouse: useful for testing changes before publishing.
Field data from real users is what Google uses, so changes can take around 28 days to be reflected in reports.
How to improve LCP
- Compress images and serve WebP or AVIF formats.
- Preload the hero image and do not lazy-load it.
- Use fast hosting and page caching.
- Use a CDN to serve files closer to visitors.
- Remove render-blocking CSS and JavaScript where possible.
How to improve INP
- Reduce heavy JavaScript and third-party scripts such as chat widgets and trackers.
- Delay non-essential scripts until after the page loads.
- Avoid bloated page builders and unused plugins.
- Break long tasks into smaller ones.
How to improve CLS
- Always set width and height on images and videos.
- Reserve space for ads, embeds and banners.
- Load web fonts with font-display swap and preload key fonts.
- Avoid inserting content above existing content after load.
Core Web Vitals on WordPress
WordPress sites can pass Core Web Vitals easily when built carefully. Use a lightweight theme, a caching plugin such as WP Rocket, image optimisation and as few plugins as possible. Read our guide on how to speed up a slow WordPress website for more tips.
Do Core Web Vitals really affect rankings?
Content relevance is still the most important ranking factor, but when competing pages are similar, page experience can make the difference. More importantly, faster pages convert better, reduce bounce rates and improve every marketing channel.
Quick Core Web Vitals checklist
- Hero image compressed and preloaded
- Caching and CDN enabled
- Unused plugins and scripts removed
- Image dimensions set
- Fonts optimised
- Mobile performance tested
What causes poor Core Web Vitals scores?
Most failing websites share the same root causes. Large, uncompressed hero images slow down LCP. Heavy JavaScript from page builders, sliders, chat widgets, analytics tags and advertising scripts blocks the main thread and harms INP. Images without dimensions, late-loading fonts and banners injected at the top of the page create layout shifts that increase CLS. Slow hosting adds delay to every metric because the server takes too long to send the first byte.
The good news is that fixing a handful of these issues usually moves a site from failing to passing. Start with the pages that bring the most traffic, such as your homepage and main service pages, then roll the improvements out across the rest of the site.
A step-by-step Core Web Vitals improvement plan
- Measure: run PageSpeed Insights on your top ten pages and note LCP, INP and CLS for mobile.
- Fix the server: move to quality hosting, enable page caching and use a CDN.
- Optimise images: convert to WebP, resize to the displayed size and preload the main hero image.
- Reduce JavaScript: remove unused plugins, delay third-party scripts and avoid heavy animations.
- Stabilise layouts: set image dimensions, reserve space for embeds and preload fonts.
- Retest and monitor: check Search Console monthly and keep performance in mind when adding new features.
Core Web Vitals for e-commerce websites
Online stores have extra challenges: product galleries, review widgets, recommendation engines and tracking pixels. Each one adds weight. Prioritise a fast product page and checkout, because those pages earn revenue. Lazy-load galleries below the fold, load review widgets after interaction and audit apps regularly. Faster stores consistently convert more visitors into customers.
How a faster website helps your business
Speed is not just a technical score. Visitors who wait less read more pages, trust the brand more and are more likely to fill in a form or buy. Paid campaigns also perform better, because landing pages that load quickly waste less ad spend. Improving Core Web Vitals is one of the few changes that benefits SEO, user experience and conversions at the same time.
Frequently asked questions
What are the three Core Web Vitals?
Largest Contentful Paint for loading speed, Interaction to Next Paint for responsiveness and Cumulative Layout Shift for visual stability.
What is a good LCP score?
2.5 seconds or less for at least 75 percent of page visits is considered good.
What replaced First Input Delay?
Interaction to Next Paint replaced First Input Delay as a Core Web Vital in March 2024 because it measures responsiveness across the whole visit.
Do Core Web Vitals affect Google rankings?
They are part of Google page experience signals. Relevant, helpful content matters most, but speed can be the deciding factor between similar pages.
Why is my mobile score lower than desktop?
Mobile tests simulate slower phones and networks, so large images and heavy scripts have a bigger impact.
How long until Search Console shows improvements?
Field data covers a rolling 28-day period, so improvements typically appear within about four weeks.
Can a WordPress site pass Core Web Vitals?
Yes. With good hosting, caching, optimised images and a lightweight build, WordPress sites pass easily.
Do page builders like Elementor hurt Core Web Vitals?
They add some code, but with careful design, optimised settings and a caching plugin, Elementor sites can still score well.
Want a website that passes Core Web Vitals?
Softnexis Technologies builds and optimises fast, SEO-ready websites. Start your project for a free speed review and a clear improvement plan.
