In Brief (TL;DR)
Core Web Vitals are the fundamental metrics Google uses to evaluate a website’s user experience, directly influencing its ranking.
Learn how to measure them and implement the right strategies to improve your site’s ranking and browsing experience.
Learn how to optimize these three indicators to improve your site’s ranking and deliver a superior user experience.
The devil is in the details. 👇 Keep reading to discover the critical steps and practical tips to avoid mistakes.
Imagine walking into a store: you’d want it to be bright, tidy, and have staff ready to answer your questions immediately. A website is no different. Its ability to welcome users quickly and efficiently is crucial. Google created a system to measure this very “quality of welcome”: the Core Web Vitals. These are specific indicators that evaluate the User Experience and have a direct impact on a site’s ranking in search results.
These metrics are not just technical details, but a true sign of respect for visitors’ time and attention. A site that loads quickly, responds promptly to commands, and doesn’t have annoying visual “jumps” communicates professionalism and reliability. Optimizing Core Web Vitals, therefore, means improving user satisfaction and, consequently, increasing your chances of online success, whether it’s selling products, offering services, or simply sharing information.
What Are Core Web Vitals?
Core Web Vitals are a set of three specific metrics that Google considers essential for evaluating a user’s real-world experience on a web page. These indicators are part of a larger group of signals known as “Page Experience,” which help Google’s algorithm reward sites that offer a smooth and pleasant browsing experience. The goal is to objectively measure three key aspects: a page’s loading speed, interactivity, and visual stability.
It’s important to note that these metrics evolve over time to adapt to user expectations. For example, as of March 2024, the First Input Delay (FID) metric was officially replaced by Interaction to Next Paint (INP), a more comprehensive indicator of responsiveness. The three current Core Web Vitals are therefore: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS).
LCP (Largest Contentful Paint): Perceived Loading Speed
What is LCP?
Largest Contentful Paint (LCP) measures the time it takes for the largest element (usually an image or a block of text) to become visible within the user’s viewport. In other words, it indicates how quickly the main content of a page loads. Think of it as waiting for the main course at a restaurant: a fast LCP reassures the user that the page is useful and working correctly. To provide a good experience, Google recommends an LCP of less than 2.5 seconds.
How to Optimize LCP
Improving LCP requires an analysis of the entire loading process. The most effective strategies include a targeted approach to making your WordPress site faster and more responsive. Here are some practical steps:
- Optimize images: Compress images without losing too much quality and use modern formats like WebP or AVIF, which are lighter than traditional JPEG or PNG.
- Improve server response times: High-performance hosting is the foundation of a fast site. Reduce the Time to First Byte (TTFB) by choosing a quality provider.
- Use a CDN (Content Delivery Network): A CDN distributes your site’s content across servers located around the world, reducing the physical distance to your users and, consequently, loading times.
- Reduce render-blocking resources: Heavy CSS and JavaScript files can prevent the page from quickly displaying its main content. Minimize these files or defer their loading (using attributes like defer or async).
INP (Interaction to Next Paint): Responsiveness to Interaction
What is INP and Why Did It Replace FID?
Interaction to Next Paint (INP) is the metric that evaluates a page’s overall responsiveness to all user interactions, such as clicks, taps, and typing. It replaced First Input Delay (FID) because FID only measured the delay of the first interaction, offering a partial view. INP, on the other hand, considers the entire page lifecycle, providing a more accurate picture of the user experience’s fluidity. Imagine talking to an assistant: FID only measured the speed of the first response, while INP assesses whether the assistant remains attentive and responsive to each of your subsequent requests. An INP value below 200 milliseconds is considered good.
How to Optimize INP
Optimizing INP mainly focuses on efficient JavaScript management, which is often the primary cause of poor responsiveness. Here are some concrete actions:
- Reduce JavaScript execution: Analyze your site’s code to eliminate unnecessary or overly heavy scripts.
- Break up long tasks: Scripts that take a long time to execute can block the browser, preventing it from responding to interactions. Break these “long tasks” into smaller, faster operations.
- Optimize event callbacks: Simplify the code that runs in response to a click or other input to ensure an immediate visual response.
- Limit the use of third-party scripts: Scripts for analytics, advertising, or social widgets can significantly weigh down the page. Load them asynchronously or only when strictly necessary.
CLS (Cumulative Layout Shift): Visual Stability
What is CLS?
Cumulative Layout Shift (CLS) measures the visual stability of a page by quantifying unexpected shifts of elements during loading. Have you ever tried to click a link or a button, only to have it move at the last second because an image or an ad banner suddenly appeared? That’s a “layout shift,” and it can be very frustrating. CLS sums up all these unexpected shifts. A CLS score below 0.1 is considered optimal.
How to Optimize CLS
Ensuring visual stability is often simpler than you might think and is based on good development and responsive design practices. Here’s how to reduce CLS:
- Specify dimensions for images and videos: Always include width and height attributes in your image and video tags. This way, the browser reserves the correct space for the element before it’s even loaded, preventing layout “jumps.”
- Reserve space for ads and dynamic content: If you insert ad banners or other dynamic elements (like iframes or widgets), define a fixed space in the CSS to prevent them from pushing the rest of the content down when they appear.
- Avoid inserting content above existing content: Don’t add new elements to the top of the page unless it’s in response to a user interaction (e.g., a click on “Show more”).
- Manage web fonts correctly: Custom fonts can cause shifts (FOIT or FOUT). Use attributes like font-display: swap to minimize the impact and preload the most important fonts.
Tools to Measure Core Web Vitals
To optimize Core Web Vitals, it’s essential to measure them first. Google offers several free tools that provide both “lab” data (simulated) and “field” data (based on real users). Combining this data allows you to diagnose problems and verify the effectiveness of your optimizations.
- Google PageSpeed Insights: This is one of the most popular tools. It analyzes a URL and provides a detailed report on Core Web Vitals for both mobile and desktop, along with practical suggestions for improving performance.
- Google Search Console: Within the “Core Web Vitals” report, you can monitor the performance of your entire site over time. This tool is valuable because it’s based on real data collected from Chrome users (CrUX report) and allows you to identify groups of pages with similar issues. Using a complete guide to Google Search Console can help you interpret this data correctly.
- Lighthouse: Integrated directly into Chrome’s Developer Tools (accessible with “Inspect”), Lighthouse runs a page analysis in a controlled environment, providing a performance score and specific suggestions for LCP, INP, and CLS.
Core Web Vitals in the Italian Context: Tradition and Innovation
In the Italian and European market, where Mediterranean culture values both tradition and innovation, a website’s user experience takes on special meaning. An artisan business selling handmade products online must communicate quality and attention to detail. A slow site (poor LCP) or an unstable one (high CLS) conveys an image of neglect, undermining the trust the brand has built on its tradition of excellence.
At the same time, innovation is a fundamental driver of the economy. A company that presents itself as modern and cutting-edge cannot afford an unresponsive site (poor INP). The digital experience must live up to the brand’s promises. For an e-commerce store selling ‘Made in Italy’ excellences, optimizing Core Web Vitals is not just a technical issue, but a strategic choice. It means offering an impeccable digital storefront that reflects the product’s quality and respects the customer’s time, turning a simple visit into a memorable shopping experience and, ultimately, a conversion.
Conclusion
Core Web Vitals are much more than just a technical SEO ranking factor. They represent a fundamental shift in how Google evaluates websites, placing the user experience at the center of everything. Optimizing LCP, INP, and CLS means building a faster, more responsive, and more stable site that will not only be rewarded by search engines but, most importantly, appreciated by users. In an increasingly competitive digital world, offering a flawless browsing experience is a concrete way to demonstrate professionalism, earn visitors’ trust, and achieve your business goals. Starting to measure and improve these metrics today is a crucial investment for the future of any online project.
Frequently Asked Questions
Core Web Vitals are a set of three specific metrics (LCP, INP, CLS) that Google uses to measure a user’s real-world experience on a web page. They evaluate loading speed, responsiveness, and visual stability, and are a ranking factor in determining a site’s position in search results.
They are crucial because they directly influence your site’s ranking on Google. A good score means providing a better user experience, which Google rewards. This leads to greater visibility, more traffic, and can increase conversions, as users prefer fast and easy-to-navigate sites.
The three indicators are: LCP (Largest Contentful Paint), which measures the loading speed of the largest element on the page; INP (Interaction to Next Paint), which assesses the page’s responsiveness to user interactions (like a click); and CLS (Cumulative Layout Shift), which checks for visual stability, i.e., whether elements shift unexpectedly during loading.
You can use several free tools offered by Google. The most common are Google PageSpeed Insights, which analyzes a single page and offers suggestions, and the ‘Core Web Vitals’ report in Google Search Console, which monitors the performance of the entire site over time based on real user data.
Some optimizations are simple and accessible to everyone, like compressing images before uploading them. Others, like modifying CSS or JavaScript files, may require technical skills. However, many platforms like WordPress offer specific plugins (e.g., for cache management) that help improve these values without needing to write code.
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