What Are Core Web Vitals in SEO and How Do They Impact on Rank?

What Are Core Web Vitals in SEO?

Core web vitals are the essential metrics Google Search Console uses to measure user experience (UX) and a website’s efficiency; it then uses this information to rank websites on search engine results pages. Therefore, core web vitals are something website creators should take seriously. Not only do they help develop and optimise your website, they also allow your website to rank higher on the results pages.


How Does Core Web Vitals Measure UX?

Google has 3 main criteria to measure UX:

Largest Contentful Paint (LCP)

This is where content download speed is measured. All elements on the web page will be measured including text, images, and videos. The full download speed for each piece of content should be no more than 2.5 seconds. The result will be measured from the content that took the longest to download.


Largest Contentful Paint (LCP) คืออะไร

How to Make Websites Download Faster

  • One thing that causes websites to download slowly is large pieces of content or high-resolution files such as .png files or videos. Therefore, to make your website download faster, you should minimise the number of these kinds of files. Saving pictures as .webp can also help speed up the downloads.
  • Remove some third-party scripts as downloading web pages containing third-party script functions like live chat or a Facebook Like box requires external data to display, therefore increasing the download time.
  • Upgrade your web hosting plan to optimise your website server. Web hosts usually offer packages that allow you to use a server with higher download speeds.


First Input Delay (FID)

First Input Delay (FID) refers to the time the website took to respond to a user’s first interaction with it. For example, when a user clicks on a call-to-action button, this will measure how long the website takes to download or transfer the data. The response time shouldn’t be longer than 0.1 seconds


First Input Delay (FID) คืออะไร

What Makes Websites Slow to Respond?

There are several causes of slow website response times. Unnecessarily overloaded scripts can be one reason that browsers take longer to process data. It usually happens to websites with not with lots of unused code, such as WordPress sites. We recommend you remove unused JavaScript as well as plug-ins that use data from third parties, so you can reduce unnecessary tasks on your website.


Cumulative Layout Shift (CLS)

Cumulative Layout Shift (CLS) measures the instability of a website’s layout, such as shifted design, fonts that are too small, call-to-action buttons that are so close to each other and could cause users to click on the wrong one, as well as unexpected pop-up ads that cause users to accidentally navigate to the wrong place. 


Cumulative Layout Shift (CLS) คืออะไร

How to Make a Website Stable

Website instability issues can be easily fixed by designing the layout carefully with the proper size font and the correct call-to-action button placement. Also, if you’ve already planned where to position your pop-up ads, you should leave enough space on the web page for the banners to show. All of this should help to create a stable website layout that provides a good user experience and encourages people to return to your site.



In summary, Core Web Vitals are the metrics that Google pays special attention to when it comes to SEO rankings, because one of the cornerstones of website development is that users must have a good experience when using websites. If you use the data measured by core web vitals correctly then you can easily improve your website, which should help it to rank higher on the SERPS and drive sales for your business.