New data from the HTTP Archive reveals that WordPress websites that are running newer versions have lower pass rates of Core Web Vitals.
More specifically, it showed that only 22% of WordPress-powered sites passed the good threshold for Core Web Vitals.
It also loses out when compared to its content management system competitors, as we can see in the graph below.
When compared to Wix and Squarespace, WordPress has struggled to keep up over the year when it comes to Core Web Vitals. Yet if we rewind to this time last year, WordPress had higher rates of Core Web Vitals scores than both Wix and Squarespace.
Yet beginning in August 2020, Wix started to focus on improving its Core Web Vitals and quickly surpassed Squarespace and within 7 months it overtook WordPress, too. In turn, Squarespace, which had not improved its scores for more than a year, put a lot of emphasis on them this June, and took over WordPress in August. 
But how about the performance of Core Web Vitals when applied to different versions of WordPress?
“How have CWV scores changed over WordPress versions?” asked Adam Silverstein, a WordPress core committer (who is someone that has access to merge code to the platform’s code based). “Are there measurable improvements in the wild after recent changes like adding native image (version 5.5), iframe (version 5.7), lazy loading, and WebP image support (version 5.8)?”
After carrying out some research, Adam found that when core additions were added, such as native image and iframe lazy loading, they had no measurable improvement on the scores of Core Web Vitals.
“Lazy loading may be too aggressive as it is applied to all images,” added Adam. “WebP adoption in WordPress has been growing since the 5.8 release, however users need to manually convert their images to WebP before uploading to take advantage of the format.
“Landing WebP as the default format for sub-sized images which was started in this ticket will have a much bigger impact by automatically converting uploaded images to WebP.”
Other interesting insights to come out of the research include the fact that 70% of websites are using the latest version of WordPress, with 88% using one of the two previous versions.
Also, overall pass rates in terms of Core Web Vitals have decreased the newer the version of WordPress.
Moving forwards, it is anticipated that this analysis could provide the foundations for enhanced Core Web Vitals tracking. 
“Basically, I wanted to create a way to measure the impact of core WordPress improvements on WordPress sites,” said Adam. “My team at Google is focused on helping improve the performance of the web at scale, and WordPress is a huge part of that!
“You may have noticed us working on features like lazy loaded images and iframes, WebP image support and now helping start the performance group. I wanted to find a way to see if our work is having a measurable impact – and not just on a vanilla WordPress site you might set up for testing, but in the wild, or real-world websites that upgrade to the latest version of WordPress. That is the goal of the dashboard.”
The WordPress dashboard now tracks the performance of Core Web Vitals by each version. This allows the new performance team to monitor Core Web Vitals progress with each new release of the platform.
PS: ArganoUV is one of the world’s leading Core Web Vitals consultancies. Contact us to see how we can work together.
