It’s May of 2021, and e-commerce retailers – along with everybody else – are about to face Google’s latest SEO metrics: Core Web Vitals, which will be part of Google’s “Page Experience” update.


The metrics, which were introduced about a year ago, will begin playing a determinative role in in the evolution of Google’s search-engine ranking algorithm. The company has delayed the official roll-out date slightly until mid-June, and the new Page Experience Signal will take full effect in August.

In one sense, the Core Web Vitals metrics are great news because they focus clearly on those aspects of site construction and function that determine three critical elements of Page Experience for users.

In another sense, it’s not-so-great news because too many websites have not yet done the work required for consistent passing scores on the new metrics.

Google’s plan is to measure Page Experience for each URL it finds, and the metrics are based on experience from within a mobile browser. And, while great Core Web Vitals aren’t a prerequisite for a page to rank highly or get into Top Stories, they’ll certainly help.

A lot.

What Are the Core Web Vitals?

Google has defined three Core Web Vitals, and each is a measure designed to inform as to friendliness and accessibility for users, and the quality of their experience on a website. Together, they account for well over half of the total rank-related speed score for a site. Site owners will find CWV reports in their Google Search Consoles.

It’s worth noting that determination of a site’s Core Web Vitals is based on “Field Data” as opposed to “Lab Data.”

The former consists of performance-related information derived from users’ actual page loads. While Lab Data (which is exactly what it sounds like) can be useful, it doesn’t necessarily reflect what users experience in real-time interactions on a site. You can use both to gain greater insights, but the CWV will use information amassed by the Chrome User Experience Report (Crux).

Here are the metrics.

◊  Largest Contentful Paint (LCP)

The “Largest Contentful Paint” targets the largest chunk of visible material a visitor will see on a page – that is, the largest chunk of content above the fold. Google uses “largest” in the sense of time required to load, rather than actual size of the content, and it doesn’t matter whether the content in question is text, an image, or a video.

Google wants the LCP to take 2.5 seconds or less for all users, with emphasis on mobile users. The indexing and ranking value of the LCP, particularly where mobile is concerned, is critical.

◊  First Input Delay (FID)

The “First Input Delay” has to do with a site’s capacity for efficient interactivity. It measures the delay of a user’s first interaction with a site through clicking or tapping – in other words, the browser’s response time to the visitor’s initial action.

Google is looking for an FID of not more than 100 milliseconds.

Given the differences in browsers and devices, there are many variables can affect the length of time it takes a site to respond. However, the usual culprit behind major delays and slow responses is the amount of JavaScript execution taking up CPU cycles in response to a user action request.

◊  Cumulative Layout Shift (CLS)

“Cumulative Layout Shift” has to do with the visual stability of the content the user sees above the fold on a site. It provides a measure of how much the visual elements of a site shift or jump around unexpectedly for reasons other than user-initiated action. Google tracks unexpected layout changes to create the CLS metric.

Google would like to see a CLS score of 0.1. The more a site’s CLS climbs, the greater the likelihood that the site needs optimization to meet Google’s new guidelines.

Of course, Core Web Vitals, while making up the lion’s share of metrics for Page Experience, aren’t the only measures Google uses.

Mobile friendliness and security (by way of safe browsing and HTTPS connections) are also parts of Page Experience, as is the absence of what Google calls “intrusive interstitials.” These are things like pop-ups that interfere with mobile users’ ability to get at the content they want on a page because an interstitial takes up too much space.

Very annoying.

Google Changes Metrics Like We Change Socks: Why Should Site Owners Care?

Well, there’s the obvious.

If you recognize the business value of having your website score well in Google’s search rankings, that alone should provide incentive for remedial action.

This isn’t about taking steps to pursue abstract goals. It’s about pragmatic measures to make your site more user-friendly and discoverable, and keep it that way.

Beyond the obvious, there’s the fact that Google is recognizing the change in web user and consumer sensibilities resulting from recent trends, and especially from users’ reactions to the events of the last 16 to 18 months.

The whole idea is to ensure that the highest ranked sites include those whose basic functions will support meaningful user experience without driving frustrated visitors away.

Seems like a simple, sensible idea – right?

It’s even more sensible when you consider that on average, you have somewhere between four and eight seconds to capture mobile users’ interest to the point of getting them to interact with a site.

The Research Doesn’t Lie: Getting Ready to Rank

Google did make known its plans for the new metrics a year ago. If current numbers are accurate, not many site owners paid attention.

A recent Searchmetrics research survey (April 20, 2021) found that approximately 90% of the sites searched on mobile devices and 96% of those searched on desktops didn’t meet the standards the Core Web Vitals require.

Hmmm. That’s, like, a couple of weeks ago.

And most of the top 20 sites in current searches didn’t meet the new standards for what Google considers a good page experience for users.

The Searchmetrics study is a large one. The research, based on analyses of more than 2 million top 20 results from three countries, indicates that even before the Core Web Vitals go “official,” sites currently doing well with them tend to do better in Google’s search rankings.

Marcus Tober of Searchmetrics had this to say in the study:

“The Google Core Web Vitals update is in many ways a response to websites not really living up to user expectations. It’s a clear message to website owners that not putting users first may have a negative effect on rankings.”

If Tober is correct – and we believe he is – then the task facing site owners is clear.

It’s not necessarily a difficult task, though it will obviously take some time and resources to streamline sites with “heavy” infrastructure or a focus that hasn’t been primarily on customer or user experience.

We think it’s also not optional – at least not for businesses and site owners wanting to strengthen their web presence, build followings, and enhance their resilience at attractiveness to users.

What Can We Do to Maintain or Improve CWV?

There are some basic things site owners can do to improve their Core Web Vitals metrics.

First, it’s theoretically possible to rank well in Google even with poor Core Web Vitals.

The proof: YouTube. However, YouTube is overwhelmingly popular for a host of other reasons that are apparently unaffected by its poor Page Experience metrics. It’s not the sort of example most other sites can emulate because they share neither its history with users nor its vast resources.

An example of a large site that does perform well with the CWV, according to Searchmetrics, is Wikipedia. Its spare layout and structure, page design, and optimized image usage have resulted in excellent CWV values.

At the most basic level, here are some areas to address and steps to take to improve Core Web Vitals values on a site.

  • Especially if you own a site built on Wordpress, get rid of old code (including third-party scripts that aren’t required for site functioning), unnecessary plugins, and unused or overweight JavaScript.
  • Optimize fonts and font-loading.
  • Employ lazy loading for images through a stable, well-tested plugin. Optimize images, and make sure they conform to the appropriate sizes and resolutions for your target devices. Remember that Google tests Page Experience on mobile devices first. The same logic applies to videos and other media.
  • Limit your use of large page elements and minify your CSS (Cascading Style Sheets) so that the visual styles you’ve set for your site or page don’t bog down the loading process.
  • Use a robust, fast cache for your site. You can start by checking some of the caching options available for Wordpress.
  • Try to “reserve space” for whatever elements you want to appear above the fold so that they appear where users expect to see them and nothing displaces them. You should also allocate space for any advertisements you intend to present.

Obviously, the utility and clarity of your user experience (UX) design positively affect your Core Web Vitals, so you may be able to make alterations that go well beyond improvement of your site’s Page Experience metrics. It’s worth having a look at Backlinko’s Page Speed and SEO page for additional insight.

Final Thoughts

Whether or not you have the knowledge and skills personally to make the changes your site needs to improve your users’ Page Experience, it’s an area in which you’ll likely need to invest. That’s the only way to deal with Google’s expectations and improve in search engine rankings.

The company has made its intent clear:

  • it wants to puts users’ Page Experience (as measured in part the Core Web Vitals) forward as a key determinant of ranking;
  • it’s going to reward sites that create a smoothly flowing experience for users; and
  • it doesn’t think users should have to endure waits resulting from slow processing, technically driven interruptions that interfere with the UX, and distractions or errors arising from unresponsive site elements.

Given the statistics disclosed by the Searchmetrics study, we feel confident in saying that it’s time for most site owners to rise to the challenge and do what they can to improve their Core Web Vitals quickly.

Google’s initiative promises to be an ongoing thing. We think it prudent to revisit your UX and check your Core Web Vitals today.