Everything you need to know about Core Web Vitals: And what they mean for you.

Do you know what Core Web Vitals are? Core Web Vitals are a set of metrics defined by Google that measure your site speeds, responsiveness and visual stability.

Last year, Google announced that they would be rolling out a significant algorithm update designed to measure the overall user experience of a webpage. The “Page Experience Update” is intended to highlight pages that offer excellent user experience through core web vitals and page experience factors.

Why Do Core Web Vitals matter To Your business?

Until recently, Google has ranked web pages based predominantly on the web page’s content (you remember SEO, right?). In the future, Core Web Vitals and page experience will join the hundreds of signals that Google considers when ranking webpages in the top search results.

Meme Boromir One Does Not Simply Ignore Core Web Vitals


What are Core Web Vitals?

Core Web Vitals are a set of real-world user-centred experience metrics used to measure how a user will experience your webpage. Alongside mobile optimisation, safe browsing, HTTPS, and not using interstitial pop-ups, Core Web Vitals will be joining a group of metrics that Google calls Page Experience signals.

Core Web Vitals are three specific page speed and user interactions methods that Google considers necessary for user experience. These three metrics are:

  • Largest Contentful Paint (LCP)
  • First Input Delay (FID)
  • Cumulative Layout Shift (CLS)

These three metrics answer the questions Google will ask when determining how user-friendly any given webpage is. How fast does a page load, how quickly is the page interactive, and how stable is the page?

Core Web Vitals Graph

Source: Core Web Vitals

Largest Contentful Paint

Largest Contentful Paint answers the question of how fast does a page load? This metric measures the time it takes from someone clicking on your website to the time it takes for them to see the majority of your content. LCP is somewhat different to other page speed measurements. Other page speed metrics, such as First Contentful Paint, don’t always represent the real-life user experience when a user opens up a webpage. On the other hand, Largest Contentful Paint is the speed at which the largest block of content loads on a web page.

LCP can be a challenge to large web pages with multiple features or high-resolution images. Primary factors affecting LCP include slow server response times, render-blocking JavaScript and CSS, resource load times and client-side rendering.

Googles guidelines break LCP speed into three categories: Good, Needs Improvement, and Poor. Ultimately, you want every page on your site to load within 2.5 seconds.

largest contentful paint example

Source: Largest Contentful Paint (LCP)

First Input Delay

First Input Delay answers the question of how quickly is your page interactive? FID measures the time from when a user first interacts with a page to the time when the browser can begin processing that interaction.

In 1968 Robert Miller published a paper called Response time in man-computer conversational transactions. In his paper, Robert Miller describes that the human mind will perceive a response time of 100-millisecond or less as instantaneous. For this reason, to provide a good user experience, sites should strive to have a First Input Delay of 100 milliseconds or less. Anything between 100 milliseconds and 300 milliseconds needs improvement, and anything above 300 milliseconds is not adequate and will likely affect your rankings.

While the recommended percentile for all Core Web Vitals threshold is the 75th percentile, Google recommends looking at the 95th and 99th percentile. FID is based on human interaction, and those percentiles will correspond to the first experience users who may negatively experience your website.

Cumulative Layout Shift

Cumulative Layout Shift, and possibly the most aggravating for most users, answers the question of how stable is your page? Visual Stability is all about whether elements on the page shift in a way that a user might not expect or cause a user to experience unexpected interactions on your site.

Cumulative Layout Shift measures the visual stability and individual layout shift changes of your web page by looking at the viewport size and the movement of two unstable elements in the viewport between two rendered frames.

The measurement of two movements determines the layout shift score: impact fraction and distance fraction. Impact fraction measures how distracting the layout shift was, with larger objects being more noticeable to users than small ones. Distance fraction, like its name implies, are the measurements of the distance that an object travels on your screen.

To provide a good user experience, Google requires pages to maintain a Cumulative Layout Shift score of less than 0.1

Cumulative Layout Shift example gif

Source: Cumulative Layout Shift (CLS)

Where do we go from here?

Google has announced that Core Web Vitals and the Page Experience Update would slowly begin rolling out in mid-June 2021 through August 2021. This gives web admins, developers, and SEO’s the time they need to prepare.

Start by using this opportunity to test the individual factors of the new page experience signal on your own website. Use the tools Google has provided, such as Google Page Speed Insights, to diagnose your problems with Core Web Vitals. We have more information on Page Speed Insights here.

It is important to remember that these changes will not only improve your ranking, but a good user experience also makes for less aggravated users with better conversion rates. Google itself says that studies show that users are 24% less likely to abandon shopping sites and page loads when a webpage meets the metrics thresholds.

Page Experiences will allow users to be more engaged with your content while making that content easily accessible.


Improving Core Web Vitals for Shopify

There are many different ways you can improve your Core Web Vitals for your Shopify store. The first step is to use Google’s tools to identify the pages that perform poorly and address those issues first. The Chrome User Experience Report collects anonymised, real user measurement data for each Core Web Vital. PageSpeed Insights provides URL-level user experience metrics for popular URLs known by Google's web crawlers. Search Console’s Core Web Vitals Report shows how your pages perform based on real-world usage data.

If the new Page Experience Update concerns you, Our On-Demand-Digital department can help you navigate these ever-changing conditions. Get in touch with us here.

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