October 8, 2021

Google Pagespeed Insights and Core Web Vitals: How Important Are They for SEO?

Let's find out the difference between the two terms and how important they are as a ranking factor.

The main question is: how important is it for successful SEO to try to score 100/100 on the PageSpeed ​​test Insights? We will talk about it in this article.

Last November Google announced that "page experience ranking signals for Google Search will be launched in May 2021. That will combine Core Web Vitals and previous UX related signals".

Google rarely tells the SEO community which part of its algorithm it considers a ranking factor, but when it does, as with the most recent BERT algorithm update announcement, we need to pay attention and make sure to align our SEO strategy to include Google best practices.

Google PageSpeed Insights is a powerful online tool for evaluating web performance. It rates the site on a scale of one to 100 and provides recommendations for further optimization. Another Google tool, Core Web Vitals , provides specific details on the actual speed of the site and user experience. Following the tips of these platforms will improve your SEO and help you push the page higher at the top of Google.


What is Google PageSpeed Insights?

While Google doesn't disclose its algorithms, at least one thing is clear: loading speed is used as a ranking factor for both on devices desktop that on mobile devices .

Google PageSpeed Insights It is useful when a website maintainer wants to analyze the performance of the site on desktop and mobile devices and determine the factors that affect the speed, efficiency and overall attractiveness of the site. Basically, it allows you to measure page load time and observe how site speed ranks.

To test a website, simply enter its URL and press the "Analyze" button:

Google Insights PageSpeed

The tool provides speed data on mobile and desktop devices and you should choose one of the options before hitting the “Analyze” button. In recent years, with mobile-first search results, loading speed on mobile devices has become much more critical than on desktop, so don't forget to check them.

The result shows an overall score that summarizes the performance of the page and further details on the factors that influence it. The score is calculated by running an automated tool open source named Lighthouse .

Most of the information you get relates to technical website performance issues. And it's a trap that so many website owners and managers fall into. When you see several very informative green, yellow and red color charts and an actual score on it, you intuitively rush to improve the metrics to bring the score closer to 100.


Does the score really matter?

The fact is, to get a top spot on the Google results page, your site doesn't necessarily have to score 100 out of 100 on PageSpeed. Insights. In fact, such an approach could even be destructive to the website, as it could require the disposal of many useful elements of UX. More important is to check if the graphs generated by the analysis are green and if they are yellow or even red, you should work on the improvement.

To show that the highest score does not guarantee the site a place among the highest ranking pages, we conducted an experiment. We searched on Google forms popular WordPress  and tested every page from the top-10 with PageSpeed Insight.

Unsurprisingly, the front page scored 42/100 and its graphs showed some yellow and red sections. Page number two scored 32/100 with a lot of red color in the infographic. Interestingly, the page in 10th place scored 84/100 with less red and some yellow.

What does it mean? The PageSpeed ​​test Is Insights useless in terms of gaining a top spot in SERPs (Search Engine Results Pages)?

Sure, it isn't. But the most valuable part of the analysis is not the impressive numbers, but the tips provided.

Why? As one of the views that PageSpeed Insights examines the page and the user experience. And the score doesn't really reflect that.

How to use Google PageSpeed ​​suggestions Insights

The loading time of the site is, without a doubt, among the most significant factors influencing user satisfaction. If people get annoyed faster than the page finishes loading, they simply bounce off. This means you should work to increase the site's throughput (can be measured with different tools) and yours perceived performance (how fast the site looks to users) instead of thinking about the highest score. This is where PageSpeed ​​tips Insights are useful.

When you analyze the site, you will find field and laboratory data.

Field data shows how a particular site is performing compared to others in the Chrome Real-World User Experience Report for the past 30 days and helps find real-world bottlenecks. In some cases, this data may non be available . To track the real user experience, Google released Core Web Vitals . This service provides specific details on the speed and real-life experience of the site. We talk about this tool later in the text.

The lab data estimates the site's performance on different metrics when loading a simulated page in a controlled environment.

The combination of field data and lab data provides a better idea of ​​the site's web performance than the overall score. With this in mind, you can proceed to suggestions for further improvements. These recommendations are called Relationship Opportunities.

More information is provided in the Diagnostics section.

Other typical weaknesses that still worked well for the indicated page can be found in the Audits Passed section.

Some of the more typical Google PageSpeed ​​tips Insights (with specific suggestions for WordPress sites)

1. Serve the image in the next generation formats

Commonly used image formats such as JPEG or PNG provide worse compression than formats such as PEG 2000, JPEG XR, and WebP. Using a form to take advantage of WebP image formats that automatically creates a WebP copy of the uploaded images can be convenient.

2. Eliminate rendering-blocking resources

This means that some JavaScript and CSS scripts slow down the page load. To optimize, PageSpeed Insights suggests incorporating critical CSS and JavaScript or consider using forms for asynchronous loading.

3. Correct image size

Properly sized images not only improve loading time but also save cellular data. For WordPress websites, it's a good idea to use native responsive image styles (available in WordPress 8 and later).

4. Send off-screen images

The postponement of off-screen images or the slow loading it means that images are loaded only when they are needed. It greatly improves perceived performance and can be achieved with the help of various stack specific modules or plugins (there are options for WordPress).

5. Minimize unused JavaScript

JavaScript might block rendering or be asynchronous, but either way it's a good idea to delete unused scripts as they slow down the page load. For WordPress, consider using only the libraries you need for the relevant page or even the particular component on a page.

6. Serve static resources with an efficient cache policy

The caching process means that browsers save copies of web pages. When the same user revisits the site, it loads faster. For WordPress, you may want to set the “Maximum age of browser cache and proxy”.

The main vital points of the Google web

I Core Web Vitals are the four measurements that represent the different aspects of the user experience. These measurements are:

1. FCP - First Content Paint

Shows the time it takes from the initial browser request to rendering any part of the page. You can improve this score by sending only the resources necessary to make what is visible to users in the viewport. For example, the inline styles and lazy loading we talked about earlier are great practices in this case.

2. LCP - The largest "Drawn" content

It measures perceived loading performance, which is the time between the initial request and when the main content of the site is ready. This score can be improved by checking font performance and using a native image tag with srcset or an image element. In general, it is a good idea to make sure that the images, text, and all content in the window are displayed with as few serial dependencies as possible.

3. FID - First Input Delay - First input delay

Measure load responsiveness or interactivity. This score is affected by heavy script processing or by rendering complex styles. Hence, it makes sense to reduce the amount of JavaScript that runs on a given page. Also, the FID is affected by the performance of the device. Don't forget to test your site on different devices.

4. CLS - Cumulative layout change

Measure visual stability. In other words, when the page content that is already loaded suddenly moves, it can be called an unexpected layout move. This experience proves extremely frustrating for users. The reason for such a mess could be resources that are loaded asynchronously or dynamically injected content. There are many tips to optimize CLS , including the reservation of space for images and ads on the site.


Fast sites with better user experience are ranked higher by Google. To optimize websites, we need a lot of measurements and PageSpeed Insights is an effective tool that provides insights into web page performance. It also provides recommendations for further optimization.

However, the overall PageSpeed Insights isn't that significant, and a score of 100/100 won't guarantee the site a top spot in Google's search results. What really matters is to focus on the suggestions or opportunities offered by the service. Another useful tool is Google Core Web Vitals. It aims to measure user experience in real life and is a must for contemporary website maintainers.

Approach these concepts through professional SEO consultancy through a SEO consultant specialist who knows the topic well is the first step in improving the positioning of your website or WordPress blog.

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