2022 Web Almanac Performance Data Shows WordPress Sites May Be Overusing Lazy-Loading

Prior to the WordPress 5.9 update, WordPress’ default of lazy loading implementation was causing slower LCP performance, because it had been applied too aggressively and was lazy-loading images above the fold, which is not needed. In 5.9, WordPress shipped a fix that more eagerly loads images within the initial viewport while lazy-loading the rest as they come into view. That’s why results that show WordPress sites overusing lazy-loading are surprising to see.

In 2020, Viscomi commented on how quickly the adoption of native image lazy-loading shot up after the WordPress 5.5 update was released in August of that year with images then being lazy-loaded by default. WordPress has been driving adoption of this feature, which is why any implementation “anti-pattern,” as Viscomi characterized it, has an outsized effect on the performance of the web.

“What gives, WordPress? My theory is that it’s not the core heuristics that are wrong, it’s the plugins. Also, keep in mind that the majority of pages that even use lazy-loading are WP. To support the plugin theory, let’s look at custom lazy-loading of LCP: More than half of the pages that do it are built with WordPress. WordPress is ‘only’ a third of the web, so there’s clearly something going on with JS-based lazy-overloading in WP.”

Rick Viscomi






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