What are Google Core Web Vitals?


12/11/2021 - No Comments


Que son los Core Web Vitals de Google

The “ Core Web Vitals ” are a Google initiative designed to measure and improve user experience on the web. Rather than focusing on generic metrics like how long it takes for the entire website to load, Core Web Vitals focus on how your site’s performance gives you a high-quality user experience.

Users worry about how quickly they can start interacting with a page. That is precisely what the Core Web Vitals metrics are intended to measure.

Currently, there are three Core Web Vitals: Largest Contentful Paint (load performance), Cumulative Layout Shift (visual stability), and First Input Delay (interactivity) .

According to Google, these metrics are the most important to offer a great user experience.

If you think these names are confusing, and if you tend to mix one metric with another, don’t worry! We will explain each metric in the simplest way. We want you to understand what each Core Web Vital means and its impact on the user experience.

It is the first step to improve the scores and your overall SEO performance.

Largest Contentful Paint

What are Google Core Web Vitals?


The Largest Contentful Paint (LCP) measures the time it takes for the most meaningful content on your site to load, which is typically the main section or featured image on your site.

According to Google, the time it takes for the main content of a page to load affects how quickly users perceive your site to load.

Practical example: you enter a page and you don’t see the top image fully displayed right away. It would be annoying, right? He would even think about leaving the page immediately. Here’s why the Largest Contentful Paint metric is closely related to user experience, rather than overall site load time.

The LCP “element” is different for each site, and it is also different between the mobile and desktop versions of your site. Sometimes the LCP element can be an image, while other times it can be just text.

If you’re wondering what a good LCP time is, here are the Google thresholds:

  • Good – Less than or equal to 2,5 seconds
  • Needs Improvement: less than or equal to 4,0 seconds
  • Poor – More than 4,0 seconds.

Side note: LCP is very similar to First Contentful Paint (FCP), another metric included in PageSpeed Insights.

The key difference is that LCP measures when the “main” content is loaded. FCP focuses on when the “first” content loads, which can be a splash screen or a loading indicator, which is less relevant to the user experience.

Cumulative Layout Shift

What are Google Core Web Vitals?


The Cumulative Layout Shift (CLS) measures how much content on your site “scrolls” or “moves” while it loads.

Practical example: you are about to click on a link or CTA (“Call To Action”), and you can’t because the content just downloaded after loading. That makes for a terrible user experience, and that’s a design change. The same is true when you accidentally click the wrong button because late-loading content caused the button to scroll.

Have you ever been to a news website where the article content scrolls as the site loads the ads, and you can’t keep reading? That is also a design change.

You can see for yourself how the cumulative layout change is super annoying for users and how they will have a bad experience.

Here’s how Google defines CLS scores:

  • Good – Less than or equal to 0,1 seconds
  • Needs Imrpovement – Less than 0,25 seconds or equal
  • Poor – More than 0,25 seconds.

First Input Delay

What are Google Core Web Vitals?


First Input Delay (FID) measures the time that elapses between when a user interacts with something on your page (for example, clicking a button or link) and when their browser can start. to process that event.

Practical example: if the user clicks a button to expand an accordion section, how long does it take for your site to respond to that and display the content?

The first input lag is probably the most difficult metric to understand and optimize, also because it is heavily affected by JavaScript.

Let’s say you land on a mobile site and click on a link, but you don’t get an immediate response. It could be because your phone is busy processing a large JavaScript file from that site.

This is how Google defines FID scores:

  • Good – Less than or equal to 100 ms
  • Needs Improvemente – Less than 300 ms or equal
  • Poor – More than 300 ms.


¿How to improve my Core Web Vitals?


We leave you a complete article with which we were inspired to write this post, from our friends at WP Rocket where you can learn more about this topic.

If you want to have a complete SEO optimization analysis and want to improve your Core Web Vitals, we invite you to know our services and contact us so that we can talk about how we can help you.





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