Core Web Vitals: What You Need to Know About Google’s Newest Ranking Signal For 2021

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  • 3/30/2021
    Every time Google drops a new announcement about its ranking algorithms, we sound the alarms, put on our helmets and gear up to go on the offensive. You just never know when an update is going to result in a huge paradigm shift for marketers. 
    Back in 2020, Google announced it would be updating its ranking algorithms to eventually include “Core Web Vitals,” a set of metrics designed to better quantify & measure the user experience of a webpage. 
    At first, Google said there was no need for immediate alarm, and that plenty of warning would be given prior to making the update. But in November, Google kept us on our toes, announcing that Core Web Vitals would officially be incorporated as a ranking signal in May of 2021. With such a short time frame, marketers are scrambling to get their websites in compliance in time for the big changes. 
    If you haven’t started your updates yet, don’t panic. Many marketers are still unaware of what Google Core Web Vitals are, let alone what potential impact they will have on their site’s organic performance. Your friends at thunder::tech are here to explain.

    What Are Google’s Core Web Vitals?

    For years, Google has used the Page Experience signal to measure how users judge the overall experience when interacting with a web page. The Page Experience signal assessed the elements that make a page user-friendly, like mobile optimization, browser safety, usage of HTTPS protocol and the intrusivity of pop-up ads. 
    Beginning in May, Google will now incorporate three new factors, collectively known as the Core Web Vitals, into their Page Experience assessment. According to Google, Core Web Vitals are “a set of real-world, user-centered metrics that quantify key aspects of the user experience.” These new elements will join forces with previous search signals to provide a more complete representation of a page’s user experience. 
    • Then = Page Experience Signal
    • Now = Page Experience Signal + Core Web Vitals

    Core Web Vitals Components & How To Improve Them

    The Core Web Vitals measurement is made up of three different factors: 
    • Largest contentful paint (LCP)
    • Cumulative layout shift (CLS)
    • First input delay (FID)
    These metrics are designed to measure loading speed, interactivity and visual stability, all of which are extremely important elements of a page’s overall user experience. Below, we’ll break down what each of these components are, how to measure them and how to improve them before the May 2021 algorithm update. 

    core website vitals

    Largest Contentful Paint

    The first Core Web Vitals metric, Largest Contentful Paint (LCP), is the speed at which a page’s main content is loaded for the user. It is measured as the largest image or block of content within the viewport. 
    Why the largest image? Long content load times contribute directly to a poor user experience, so it’s important to ensure your content is loading quickly. In order to have what Google considers a “good” LCP, your page’s main content should load within 2.5 seconds of a landing on the page. 
    If your page has a poor LCP, it is likely the result of one of four factors: 
    1. Slow server response time
    2. Render-blocking Javascript and CSS
    3. Slow resource load times
    4. Client-side rendering 
    For a full breakdown of how to improve these elements, check out Google’s guide on how to optimize LCP. One more important point: since Google uses mobile-first indexing, it’s advised to optimize your LCP on mobile before desktop. 

    Cumulative Layout Shift

    The second element of Core Web Vitals, Cumulative Layout Shift (CLS), measures how often unexpected layout shifts occur on a page. In other words, CLS measures the visual stability of a page. If on-page elements like text, fonts, images or buttons are moving around on the page unexpectedly, this can cause a poor user experience. 
    In order to “pass” this checkpoint, your page should maintain a CLS of less than 0.1. FYI, this number is derived by multiplying your distance score by your impact score, and the math could be its own blog. Just know you want as little CLS action as possible on your page.
    The biggest contributors to a poor CLS are images without dimensions, ads, dynamically injected content, web fonts and actions that wait for a network response before updating the DOM. According to Google, there three simple principles to follow in order to avoid unexpected layouts shifts:
    1. Always include size attributes on your image and video elements
    2. Never insert content above existing content expect in response to a user interaction
    3. Perform transform animations to animations of properties that trigger layout changes
    For ad-heavy sites and sites with a large amount of dynamic content, maintaining a CLS of less than 0.1 might be difficult. For more information on how to optimize a page’s Cumulative Layout Shift, refer to this guide from Google

    First Input Delay

    The final part of the new Core Web Vitals is the First Input Delay (FID), which describes how fast a user can interact with a page after they’ve landed on it. Technically speaking, FID measures the time from when a user first interacts with a page to the time when the browser is actually able to begin processing event handlers in response to that interaction. Ideally, this event should happen within 100 milliseconds after a user arrives on a page. 
    Input delay, or input latency, occurs when a browser is busy and as a result, is unable to process an action from a user. Typically, this occurs when a page has a large amount of Javascript code that needs executed. In order to improve your FID, optimize your Javascript code: how it parses, compiles, and executes. This can be done by dreaming down long code into smaller, asynchronous tasks, reducing Javascript size bloat and running Javascript in background threads through the use of web workers. For a full breakdown of how to lower your First Input Delay, refer to this more in-depth article from Google. 

    How To Measure Core Web Vitals

    Like the Marvel Cinematic Universe, Core Web Vitals really only work when packaged together as one rather than standalone concepts. Google’s John Mueller recently said that all three Core Web Vitals metrics must meet the minimum threshold for a page in order to be eligible to receive any boost from the ranking signal. Only optimizing your First Input Delay may help your overall user experience, but it will not provide a direct boost to your rankings without an optimized Largest Contentful Paint and Cumulative Layout Shift.  
    When originally announced, the only way to measure Core Web Vitals was through the Chrome UX report. Now, there are a number of ways to accurately measure a site’s Core Web Vitals performance, both at individual page level & aggregately for the whole site at once. Below are some, but not all of the ways to assess your site’s Core Web Vitals:
    • PageSpeed Insights - PageSpeed Insights (PSI) reports on the performance of a page on both mobile and desktop devices, and provides suggestions on how that page may be improved
    • ScreamingFrog - Through metrics supplied by the Chrome User Experience report with an API, Screaming Frog can assess Core Web Vital data across each page on a site
    • Search Console - Within Google’s Search Console, the Core Web Vitals report shows URL performance grouped by status, metric, and URL groups
    • Web Vitals Extension - A Chrome extension that measures the Core Web Vitals, providing instant feedback on loading, interactivity and layout shift metrics.
    • Chrome DevTools - Chrome DevTools is a set of web developer tools built directly into the Google Chrome browser
    After you’ve determined how you’re going to measure your site’s Core Web Vitals, the next step is to create a workflow to assess and prioritize potential changes. Google suggests using the Search Console Core Web Vitals report to quickly identify groups of pages that require attention and then diagnose specific issues on a page-by-page basis using the Page Speed Insights tool.

    Search Console’s Core Web Vitals Report
    Search Console’s Core Web Vitals Report

    How Will This Change Affect My Rankings?

    On a recent Search Central Live Fireside Chat, Google’s Danny Sullivan shared how the upcoming integration of Core Web Vitals as a ranking signal might impact current keyword positions. He noted that it shouldn’t cause significant damage, and that it's just one ranking factor out of many, many more. He added that Google’s number goal is to serve up the most relevant content it can, and that a good page experience won’t override having the best content. 
    In response to questions on Core Web Vitals on Twitter, Danny also suggested that over time this signal may become more valuable as more and more sites take page experience into consideration: 
    Tweet from danny sullivan
    Based on this guidance and other information from Google, it doesn’t sound like the rollout of Core Web Vitals will make or break a website’s rankings overnight, but rather act as a tiebreaker between pages that provide equivalent levels of relevant content. 

    Should I Optimize My Site’s Core Web Vitals?

    As some have noted, the ability to fix Core Web Vitals issues is often hindered by a slew of potential roadblocks, the most prominent of which include the need for development resources and limitations imposed by CMS platforms. For some lean marketers, these limitations might mean a complete barrier to entry. 
    Additionally, since all three Core Web Vitals metrics must be met for a page to benefit from the ranking signal boost, the time & resource outlay to fix these issues has the strong potential to outweigh the value of the ranking factor, especially if a page is already highly optimized for the other ranking signals compared to its closest competition.
    If you’re worried about your site not passing the Core Web Vitals assessment, you’re not alone. In fact, a study from Screaming Frog noted that of 20,000 URLS analyzed, only 12% of them passed the Core Web Vitals assessment. Based on the low compliance rate and ambiguity of potential impact, it seems like Core Web Vitals won’t be a huge disruption to the SEO world, nor will it cause massive changes to current rankings. 
    At most, the integration of Core Web Vitals as a ranking signal only has immediate implications for highly competitive sites, and shouldn’t cause panic for the majority of site-owners. Over time, this may evolve and become a more central focus of SEO, but for now, marketers should continue to prioritize other factors, specifically serving up the most relevant content they can. 
    Need a little help getting your website compliant? Let’s work together to keep your top-ranking pages where they are. Learn more about thunder::tech’s web design and development services here.
    About the author::Mike Ulanski is a Digital Marketing Strategist at thunder::tech, where he's responsible for driving a variety of paid & organic efforts. When not online, he enjoys adventuring with his dog & listening to live music. 
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