WordPress 5.9 to Fix Lazy Loading Performance Regression, Resulting in 30% Faster Page Loads in Some Cases

WordPress sites may soon see a slight performance improvement on page loads, thanks to a fix for a performance regression in the core lazy loading feature. An analysis published in July 2021 showed that lazy loading applied too aggressively can have a negative impact on performance and that it’s better to eagerly load the images within the initial viewport.

“This can be improved by skipping addition of loading='lazy' for the first content image or iframe, which in the vast majority of cases will appear within the initial viewport,” Felix Arntz said in the dev note. “WordPress can only make educated guesses around that and not be 100% certain, but an analysis taking into account 50 popular themes showed that the enhancement brought LCP improvements across the board, up to 30% faster page load.”