Google considers user experience in its search engine to rank pages.

It is not new. Already, some page experience signals validate whether a web page is optimized for mobile or whether the website is secure.

In its journey to offer a “better web” and ever richer user-centric experiences, Google has announced new ranking factors related to the Page Experience in 2021: The Core Web Vitals.

The Core Web Vitals metrics relate to your website’s page loading speed, responsiveness, and visual stability and have been considered in Google Search’s algorithm since May 2021. 

In this guide, you are going to learn

  • What are the Core Web Vitals
  • What is the impact of the Core Web Vitals for SEO
  • What free SEO tools to test the Core Web Vitals 
  • How to measure the pages experience of your website with the Search Console
  • And finally, how you can fix the Core Web Vitals on your website

Let’s build a better page experience together and optimize your website.

Google and the user experience

Google’s mission is to provide the best experience for users of its search engine.

You might like or dislike it, but Google shapes the Web and invites (or forces) website owners to follow the “best” practices.

Google’s initial mission (in 1998) was to organize the world’s information and make it universally accessible and useful.

For its 20th anniversary, Google reminded us of the fundamental principles of “Search”. The most important ones are:

  • First and foremost, we focus on the user. Whether you’re looking for recipes, studying for an exam, or finding information on where to vote, we’re focused on serving your information needs.
  • We strive to give you the most relevant, highest-quality information as quickly as possible. 

To optimize content for SEO (or for Google Search Engine), it is necessary to put the user in the centre and offer complete content, with structured information and also an excellent page experience.

Google wants quality content on pages loading quickly on its search engine.

Let’s look at the page experience and what it means for Google.

What’s the page experience in Google’s eyes?

The Page Experience is a set of signals measured by Google to see if your pages provide a good experience when users visit your site.

For example, Google tries to understand if your page loads fast and is optimized for mobile.

All of the following page experience signals are taken into account to measure a “good page experience” in Google search and are used as a ranking factor:

  • Mobile-friendliness: Your page is optimized for mobile browsing.
  • Safe-browsing: Your page does not contain any malicious (malware) or misleading content (phishing).
  • HTTPS security: The page is served in HTTPS.
  • No intrusive interstitials: Your page should not have elements that obstruct your main content (such as a popup covering most of the content immediately after the user land on your page… so annoying).
  • Core Web Vitals: The page provides a great user experience, focusing on loading, interactivity and visual stability.

Most top-ranked websites are already implementing signals such as Mobile-Friendly, HTTPS, safe-browsing and no intrusive interstitials.

This study from 2018 shows that 75% of websites are mobile-friendly.

But do all these sites offer an exceptional experience?

Since 2021 Core Web Vitals has been a signal for Google to define a good page experience on mobile. Note that Core Web Vitals have been part of the desktop ranking systems since February 2022.

The table below summarizes the page experience signals and if they apply to Mobile or Desktop.

Largest Contentful Paint (LCP)YESYES
Cumulative Layout Shift (CLS)YESYES
First Input Delay (FID)YESYES
Absence of intrusive interstitialsYESYES
Mobile friendlinessYESNO

The best resources to understand the Page Experience and Core Web Vitals  

Core Web Vitals

Let’s take a detailed look at what is behind the acronyms LCP, FID and CLS – the metrics of Core Web Vitals.

Free Tools To Test Core Web Vitals

To understand what is wrong with your website and improve the Core Web Vitals, you must test and measure these metrics.

Analyzing Core Web Vitals with Search Console

Review step by step how to leverage the Search Console to understand the issues with the user experience and Core Web Vitals on your website.

Tips to improve Core Web Vitals

In this article, we share several tips to help you fix your CLS, LPC and FID issues.


  1. Thanks for your article. But what do you think: When Google switches over completely to the mobile index/crawler in the near future, will the Cumulative Layout Shift (CLS) of the new Web Vitals for Desktop still be an issue? So it is enough to aim for a good CLS value for mobile and desktop can be neglected? What do you think or how do you deal with it?

  2. Hi Roland, 

    Thanks for your comment. You have great questions.

    I’m not John Muller from Google, but let me give you an answer 🙂 Or at least what I assumed.

    By switching to mobile-first indexing, Google is inviting website owners to follow a mobile-first approach while doing design and UX. Google recommends a responsive web design approach. 

    Will be CLS for desktop an issue or should it be neglected?

    My opinion is that by applying the best practices of modern web design and optimizing your website for mobile, you will at the same time optimise it for desktop. 

    Overall, think about your users first, offer them the best experiences on both devices – and in priority on the device they use to visit your site. 

    What should not be neglected is the user experience.


  3. Wreszcie znalazłem precyzyjny opis w tym temacie dzięki będzie przydatny w optymalizacji mojej strony

  4. Hey Samuel Schmitt,
    It’s a cool preparation, You have done a good job. As a web developer I almost come across all these optimization processes.

  5. Very detailed tutorial, really loved reading it and implementing it on my website. It helped me to improve my website a lot, now few things left, hope to get them sorted out too.

  6. bonsoir Samuel
    vraiment la “bible” sur les Core Web Vitals.
    Comme Josh, “J’aime vraiment le langage clair autour de LCP, FID et CLS”.

    a noter 2 choses: Le LazyLoad pour les images est natif à partir de WordPress 5.5.

    Pour minifier le code HTML, CSS et JS, il y a un excellent plugin sur WordPress : Autoptimize. (je suis justement en train d’écrire un article dessus en utilisant , en concomitance le plugin de cache WP Fastest Cache).

  7. As a fellow SEO expert, I appreciate your insightful blog post on optimizing websites for Core Web Vitals and Page Experience.

    Google’s emphasis on user experience in search engine rankings highlights the importance of prioritizing page speed, responsiveness, and visual stability.

    Your guide on the Core Web Vitals metrics, impact on SEO, and free SEO tools for testing are helpful for web developers and marketers looking to improve their website’s page experience.

    I recommend young SEOs’ learn more about search engine optimization from this blog & future posts.

    I also want to recommend my blog on search engine optimization & freelancing, Where I share my case studies and practical knowledge.

    Agha Sahad Khan

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