Time to Read: About 7-8 minutes
Intended for: Marketers, content creators, or those tasked with your websites’ SEO
Key takeaway: Core Web Vitals is a major Google-announced update to their search algorithm. Set to launch sometime in 2021, Core Web Vitals will reward sites with a good user experience and penalize those with a poor one. Take steps now to ensure you’re ready when it launches.

Core Web Vitals: If you think it sounds like the latest nutritional supplement or weight loss fad, you’re probably not alone. But it’s actually the latest major Google-announced update to their search algorithm. Core Web Vitals has the potential to have a major impact on your website’s Search Engine Optimization (SEO). What is Core Web Vitals, and what will it attempt to measure? How will it impact your websites and pages? When will it roll out? Keep reading to find out.

Changing the rules of SEO…again

Set to launch sometime in 2021, Core Web Vitals seeks to reward sites that have a good user experience and conversely, penalize sites that have a poor experience. Have you ever browsed to a website on your mobile device, and the page is nearly loaded, and then an element you were trying to click moves somewhere else on the page? Have you ever had a site load so painfully slowly that you gave up? Have you ever had a site load, but it seemed completely unresponsive to any kind of input? These are all scenarios that Core Web Vitals will attempt to address.

Important note: Remember that Google’s algorithm measures hundreds of different things to determine a page’s ranking in search results. While Core Web Vitals will surely be an important piece of the puzzle, it is only one of many factors. SEO essentials, such as unique and useful content, meta descriptions, alt text, etc. remain just as important today as they have always been.

The three components of Core Web Vitals

Core Web Vitals attempts to answer three questions:

  • How quickly does a page load?
  • How quickly does a page become interactive?
  • How quickly does a page become stable?

If you’ve ever used Google PageSpeed (powered by Lighthouse), then you may be familiar with the terminology around Core Web Vitals. The three metrics used are called: Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS). According to Google, if a website meets the “Good” criteria for all three Core Web Vitals metrics, users are 24% less likely to abandon. That’s a massive amount of potential leads, buyers, and clickers who will stick around on your website to take a desired action!

Largest Contentful Paint (LCP): How quickly does a page load?

A graphic of Largest Contentful Paint (LCP), showing that less than 2.5 seconds is good, 2.5 to 4 seconds needs improvement, and longer than 4 seconds is poor.

This one is pretty easy to wrap your head around. Largest Contentful Paint (LCP) attempts to measure how fast the first piece of content becomes visible to the user. Said another way: LCP measures when the largest content element in the viewport (or for simplicity’s sake, the active browser window) becomes visible. It is influenced by server response time, CSS, JavaScript, client-side rendering, image size, video, Content Distribution Networks (CDN), and more. Slow sites = bad news. Less than 2.5 seconds is considered good, 2.5 seconds to 4 seconds needs improvement, and anything longer than 4 seconds is considered poor.

First Input Delay (FID): How quickly does the page become interactive?

Graphic of First Input Delay (FID), showing that less than 100 milliseconds is good, 100 to 300 milliseconds needs improvement, and greater than 300 milliseconds is poor.

First Input Delay (FID) measures the time from when a user first interacts with a page to the time when the browser is actually able to respond to that interaction. Asked as a question: When a user clicks on something, how fast can the browser start to process that and produce a result? FID is influenced primarily by JavaScript and third-party code. Less than 100 milliseconds is considered good, 100 to 300 milliseconds needs improvement, and anything longer than 300 milliseconds is considered poor.

Cumulative Layout Shift (CLS): How quickly does the page become stable?

A graphic of Cumulative Layout Shift (CLS), showing that less than 0.1 is good, 0.1 to 0.25 needs improvement, and greater than 0.25 is poor.

Cumulative Layout Shift (CLS) looks at how much visible content shifted in the viewport (again, think “browser” when you read this word), as well as the distance the elements impacted were shifted. Think back to the scenario at the start of this post: You load a page on your phone, try to click a button, and the page shifts at the last second and your button moves somewhere else on the page. CLS is primarily influenced by undefined image sizes and some animations. Less than 0.1 is good, 0.1 to 0.25 needs improvement, and greater than 0.25 is poor.

Core Web Vitals: What will the impact be on my websites?

As with any upcoming algorithm update, the short and simple answer is: We don’t know. Some updates have a very large impact on a lot of sites’ rankings…think “Mobilegeddon” in 2015. Some updates have a relatively minor impact on ranking. To be on the safe side, it’s best to assume Core Web Vitals will have a major impact on your organic search ranking, and take action to ensure your sites have a good user experience. A good user experience should always be a topmost priority, anyway.

Core Web Vitals: How to Measure

Google LightHouse logo.

There are a couple of free tools available today to assist with measuring Core Web Vitals.

My suggestion: Go into Google Analytics or your favorite Analytics tool of choice. Find the 25 most-viewed pages on your website(s) for the last 90 days. Analyze each of those pages with Google PageSpeed and see what the results are for each page. Note the recommendations and speak to your development team about what it would take to start to implement some of the recommendations

As we wrap this up, keep in mind that Core Web Vitals will be just one of hundreds of signals that determine a page’s rank in search results pages. Continue to follow SEO best practices, but start getting ready today for Core Web Vitals to drop in 2021. As we get closer to its rollout, we’ll post additional information as it becomes available. If terms like organic search, SEO, and search algorithms are fairly new, reach out and let’s talk about your website’s SEO.

Bonus content: A history of Google’s algorithm updates

As I mentioned above, Google updates their algorithm all the time. If you want to geek out a little more, below is a recap of some of the major Google search algorithm updates over the years:

Universal search2007Combined different types of results (web, images, news, video, etc.) into one set of results.
Google Suggest2008Added “search as you type” suggestions to the search box.
Caffeine2010Provided “fresher” results and a much larger index.
Panda2011Rewarded pages with unique, compelling content (and penalized pages with thin/low-quality content)
Exact Match Domain2012Penalized exact match domains that were also poor quality sites with thin content.
Page Layout Update2012Penalized pages with too many ads “above the fold.”
Penguin2012Introduced to combat “black hat” spamming techniques.
Hummingbird2013Shift to meaning and intent vs. literal interpretation of queries.
Payday2013Penalized spammy sites and queries.
“Https”2014?It’s not entirely clear when this rolled out, but Google started ranking secure (https) sites higher.
Pigeon2014Changed the way businesses rank. Rewards local businesses with a strong organic search presence.
“Mobilegeddon”2015Improved ranking for pages in Google’s mobile index that had a good mobile experience, and penalized pages with a poor mobile experience. Did not affect rankings for pages in the desktop index.
RankBrain2015Introduced machine learning into search. Continued to build on the Hummingbird update. Seeks to understand user intent and meaning of phrases.
Fred2017Penalized pages with low-quality content meant to generate revenue
Intrusive Interstitials2017Penalized pages with intrusive popup ads that affect the mobile user experience. 
Core Web Vitals2021Will reward websites with a good user experience. Joins a group of metrics called “Page Experience Signals.”