HomeWordPressWordPress Core Web Vitals - What Is It And How to Measure

WordPress Core Web Vitals – What Is It And How to Measure


You may have spent much time and effort creating a jazzy WordPress website. A user-friendly interface on any website is essential. It creates a great user experience. And that’s where WordPress Core Web Vitals becomes relevant.

Intuitive UIs ensure visitors can easily navigate your website’s different sections. This increases engagement and retention, increasing the chances of meeting your goals. The side benefit is also increased professional branding for your product or service. But there is no objective way to measure the user experience provided by your website.

There are several ways by which you check the user experience. And determine whether it meets Google’s UI standards. Here I am touching on three popular tools that web developers use:

  1. Leverage Google Analytics to track click trails on your website. It helps you understand your users’ navigation paths. It also helps to understand the most engaging website sections.
  2. A/B testing is a popular method of comparing many test versions of your website. You can determine which elements create a good user experience. And which needs improvement. You can do this by observing user interaction within each version.
  3. Google’s Lighthouse is a tool deployed to measure the performance of your website. This is done across various metrics like accessibility, performance, best practices, etc.

This brings us to a point where we need to understand the concept of Web Vitals and their significance.

What are WordPress Core Web Vitals?

In May 2020, Google launched a new effort called Web Vitals. This was aimed to ensure a standardized user experience on the Web. They did it by providing unified guidance for crucial indicators of quality.

It aims to simplify the landscape and help site owners focus on the metrics that matter most. Core Web Vitals are metrics in Google’s “page experience” rating for WordPress sites. These scores are taken into consideration when ranking web pages.

It is important to clarify one key aspect in this context. Assume your WordPress site has a fantastic page experience score. This does not automatically place you in the top position in Google search results. Google emphatically clarified this in the past. Page experience is only one of many (200 Google ranking factors) variables they use to rank websites in search results.

WordPress Core Web Vitals

Core Web Vitals are essential for delivering a great user experience. Within the Web Vitals landscape, there are also other metrics to consider. These Other Web Vitals act as a stand-in or supporting metric for the Core Web Vitals. They give a more comprehensive view and support identifying specific problems.

The Core metrics are :

  • Largest Contentful Paint (LCP)
  • First Input Delay (FID) – this will be replaced by Interaction to Next Paint (INP) from March 2024
  • Cumulative Layout Shift (CLS)
Core Web Vitals
Core Web Vitals

These metrics help developers identify areas that provide a better user experience. It helps to identify areas that need website improvement. Google also guides on improving each metric. These guides help developers optimize their websites for better performance. We will touch upon this aspect later in this article.

Let’s briefly understand each of these metrics.

Largest Contentful Paint (LCP)

The Largest Contentful Paint (LCP) measures a website’s performance. This performance measure is timing how long it takes for the most prominent featured image or text block to load. A good LCP score is under 2.5 seconds. The table below gives the full range of scores, including a Poor one.

First Input Delay (FID)

The First Input Delay (FID) measures how long a user can interact with a website. For example, clicking on a button or link and that being processed by the browser. A good FID score should be under 100 milliseconds, while greater than 300 ms is considered poor.

Update: Google announced in May 2023 that FID will be replaced by Interaction to Next Paint (INP) starting May 2024. INP is a measurement of the responsiveness throughout the lifecycle of the page.

Cumulative Layout Shift (CLS)

The Cumulative Layout Shift (CLS) measures unexpected layout shifts. These shifts shouldn’t occur as the user engages with the content. Content shifting happens on a page due to loading images, ads, or other elements. A good CLS score should be under 0.1 and ideally at 0.

Wordpress Core Web Vitals
Core Web Vitals Metrics

Here’s a quick 10 mins video to further explain Core Web Vitals.

Core Web Vitals Explained: How To Fix Site Optimization Issues

How do I check my Core Web Vitals?

Web admins can measure the performance of their websites accurately. They use Google tools such as Chrome UX Report and Page Speed Insights. Google Search Console’s Core Web Vitals report is another important one.

The Chrome User Experience Report (CrUX) provides user experience metrics. The metrics reflect how real-world Chrome users experience popular destinations on the Web. It collects anonymized, actual user measurement data for each Core Web Vital.

Page Speed Insights (PSI) assesses the user experience of a page on desktop and mobile devices. It also provides helpful advice on how to enhance that page. Besides, PSI provides both lab and field data about a page.

The Core Web Vitals report shows your pages’ performance. This performance is based on real-world usage data, sometimes called Field Data. The Core Web Vitals report shows URL performance grouped by

  • Status (Poor, Need improvement, Good)
  • Metric type (CLS, FID, LCP)
  • URL group (groups of similar web pages)
Core Web Vitals result
Core Web Vitals result

It is also possible to track Core Web Vitals through JavaScript. This tracking is done with the help of conventional web APIs. For example, web developers can take advantage of the web-vitals JavaScript library. This library offers an effortless way to measure each metric with function calls. You can find more information on the process in this Github documentation.

These Website monitoring tools measure the performance of WordPress websites in real time. With this data, web developers optimize their sites. This ensures users have the best possible experience.

How do I fix Core Web Vitals issues?

Optimizing Web Vital Metrics
Optimizing Web Vital Metrics

Now you’ve figured out how to monitor and measure these metrics. It’s time to understand how to fix Core Web Vitals metrics to optimize performance and speed up your WordPress site. Below are the three high-priority actions to improve core web vitals.

Optimize the Largest Contentful Paint (LCP)

  1. Upgrade your web host: good quality hosting closer to the region of your end users. Implement a Content Delivery Network to improve user experience. This means faster load times (and better LCP).
  2. Remove heavy page elements and set up lazy loading: Google PageSpeed Insights indicates such elements on your page. They slow down your LCP. Lazy loading sets up your screen, so images only load when the reader scrolls down your page.
  3. Remove unnecessary third-party scripts & Minify your CSS: Bulky CSS Files can significantly delay LCP times. Third-party scripts don’t add value and add to the processing time (and hence higher LCP).

Optimize First Input Delay (FID)

  1. Leverage browser cache: Page loading speeds dramatically increase when you use browser cache. This speed increase happens since server trips get reduced.
  2. Minimize (or defer) JavaScript: Users cannot interact with a page while JS loads in the browser. You will need to effectively handle this aspect to improve FID.
  3. Remove used third-party scripts: Third-party scripts that take time. They may interrupt user interactions and impact the FID score.

Update: Interaction to Next Paint (INP) will replace the metric FID starting March 2024.

Optimize Cumulative Layout Shift (CLS)

  1. Add UI elements below the fold: As the page loads on the user, content stays where it is and doesn’t get pushed down.
  2. Ad spaces should be predetermined: As pages load in the user’s browser, content may shift down or side where the ads suddenly appear. This doesn’t help the CLS score.
  3. Use set size attribute dimensions for all media (like video and images): It helps if the browser knows exactly how much space each media element will need. Ads appearing in an ad-hoc manner could push away the content. In such a manner, media also can contribute to poor CLS scores.

You may go through these comprehensive guides that provide specific advice. This advice is for optimizing your pages for each Core Web Vitals.

Optimize LCP  |  Optimize FID  |  Optimize CLS

I would recommend trying WP Rocket to improve performance in WordPress. A caching plugin like WP Rocket has user-friendly settings to easily set up the Core Web Vitals.

Additional Web Vitals

Core Web Vitals are essential for providing a great user experience. They are considered critical across Google’s tools. Other web vitals must also be considered. The Other Web Vitals depend on the type of web page and the elements within it.

They often serve as a proxy or supplemental metric to the Core Web Vitals. They help measure a significant part of the user experience.

Examples of Additional Web Vitals

Examples are First Contentful Paint, Speed Index, Time to Interactive, Total Blocking Time, and Page Performance Scores. These are, however, not part of the Core Web Vitals bucket because they cannot be measured on the field (Lab only).

In addition, the other Web Vitals may be more specific to a particular situation or web elements. They are more exploratory than the Core Web Vitals.


Is it necessary to implement Core Web Vitals? I am sure you now understand Core Web Vitals are essential for providing a great user experience. They are considered critical across Google’s tools.

They measure a page’s loading, interactivity, and visual stability. This provides insights into users’ experience perception of interacting with a website. Web admins should ensure that their pages load quickly. They must also ensure the pages are interactive and reduces the avoid large layout shifts. This maintains good Core Web Vitals scores for their website.

They should regularly run Speed tests to ensure optimum load times. Web admins should also consider Other Web Vitals to gain further insights into UX.

The Core Web Vitals apply to all websites and can be seen across various Google tools. Modifications to these metrics will have extensive implications. So, developers can consider the outlines and thresholds of the Core Web Vitals to be firm. Any updates from Google will have a prior warning.

Do share your comments on how you improved user experience using WordPress Core Web Vitals.

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Prashant Shetty
Prashant Shetty
Prashant is a Technology Industry Veteran with 20+ years of experience in the field. He loves reading, music, and blogging about technology in the context of Life. He craves for a cup of sugarless black masala tea and is a religious runner.


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