Core Web Vitals – What Is It?

As early as 2010, Google introduced page speed and made it a ranking factor for desktop search. And in July 2018, they further announced that page speed will impact mobile search rankings as well. Come May 2021, Google intends to up the ante on page experience, adding Core Web Vitals to existing ranking signals such as mobile friendliness, safe browsing, encrypted HTTPS connection and guidelines on intrusive interstitials to form what is now known as the Google Page Experience update.

What Exactly Is Core Web Vitals And How Does It Differ From Page Speed?

With Core Web Vitals, Google is moving away from looking purely at how fast a page loads, to having a more holistic page experience for users. In summary, in addition to looking at loading speed, Google now wants to incorporate responsiveness as well as visual stability signals into the way they look at page experience. They have also indicated that their work in this area is on an ongoing basis with the possibility of more signals being added on a yearly basis. For now, Core Web Vitals comprises of the following:

  • Largest Contentful Paint (LCP) which measures loading speed
  • First Input Delay (FID) which measures responsiveness and interactivity
  • Cumulative Layout Shift (CLS) which measures the visual stability of the webpage

Largest Contentful Paint (LCP) measures how fast the main content on the user’s screen renders. As such it measures how fast users can begin consuming the most important content of a page. It recognises rightly that users don’t really care how long the entire page takes to load. Instead, what’s important to them is when they can start seeing the content and LCP measures this. The benchmark to obtain a good LCP score is below 2.5 seconds.

First Input Delay (FID) measures the time interval between when a user first performs an action on a page (e.g. clicking a button or a link) and when the browser begins to process that action. In short, it’s a responsiveness and interactivity measure. And to have a good score is this area, you need to aim for a FID of below 100 milliseconds.

Cumulative Layout Shift (CLS) measures the extend with which content within a screen shifts while loading. In short, it measures the stability of content within a viewport. To do well in this area, you will need to obtain a score of below 0.1.

What You Need to Know

While Core Web Vitials will become a ranking signal from May 2021, it is likely to be a lightweight signal, much like HTTPS. Google has also announced that for now, it will only be considered for mobile search. Hence, those hoping for a large ranking boost from getting a good Core Web Vital score will likely be disappointed. When it comes to Google rankings, content is still king or more specifically, content relevant to searchers’ intend.

That said, it is still a signal webmasters should pay attention to. Why? Because it improves the overall page experience for your users when they interact with your website. A good user experience generally translates to lower bounce rate and higher sales conversion. In short, it leads to higher profits.

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I'm a web design and SEO trainer in Singapore. To date, I've trained more than 5,000 people in SEO and WordPress web design. I love reading stuff related to digital marketing and especially enjoy public speaking. Prior to becoming an entrepreneur, I worked 18 years in the life insurance industry - 4 years in HSBC Insurance as the Chief Agency Officer and another 14 years in AIA, with my last role there being that of Regional Director of Agencies.

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