Weston Ruter

This is a workaround for sites experiencing any issues with the ability introduced in WordPress 6.9 to <a href="https://make.wordpress.org/core/2025/11/18/wordpress-6-9-frontend-performance-field-guide/#load-block-styles-on-demand-in-classic-themes" rel="nofollow ugc">load block styles on demand in classic themes</a>. The known issues have been fixed during the 7.0 release cycle with the following commits:
<ul>
<li><a href="https://core.trac.wordpress.org/changeset/61076" rel="nofollow ugc">r61076</a>: Script Loader: Fall back to hoisting late-printed styles to end of HEAD if wp-block-library is not enqueued.</li>
<li><a href="https://core.trac.wordpress.org/changeset/61122" rel="nofollow ugc">r61122</a>: Script Loader: Load block styles on demand in classic themes even when wp-block-styles support is absent.</li>
<li><a href="https://core.trac.wordpress.org/changeset/61174" rel="nofollow ugc">r61174</a>: Script Loader: Improve hoisted stylesheet ordering (in classic themes) to preserve CSS cascade.</li>
<li><a href="https://core.trac.wordpress.org/changeset/61554" rel="nofollow ugc">r61554</a>: Script Loader: Preserve original CSS cascade for classic themes when hoisting late-printed styles.</li>
<li><a href="https://core.trac.wordpress.org/changeset/61945" rel="nofollow ugc">r61945</a>: Script Loader: Refine hoisted stylesheet ordering to preserve original CSS cascade in classic themes.</li>
</ul>
If running a classic theme (i.e. not a block theme), this plugin filters <code>should_load_separate_core_block_assets</code> to be <code>false</code>. This has the effect of reverting a change introduced in 6.9 where classic themes now load separate core block assets on demand by default.
Note that this plugin should be considered temporary until any issues are resolved in 7.0. At any time, you can test whether any issues remain by adding <code>?should_load_separate_core_block_assets=true</code> to any frontend URL; this restores the default behavior in WP 6.9.
This workaround should be temporary because there are performance benefits to loading separate core block assets. They can be loaded on demand just when they are used, as opposed to loading the large single combined <code>wp-block-library</code> stylesheet. Loading separate block styles on demand reduces the amount of CSS which should improve page load time. Nevertheless, as explained in the <a href="https://make.wordpress.org/core/2025/11/18/wordpress-6-9-frontend-performance-field-guide/#load-block-styles-on-demand-in-classic-themes" rel="nofollow ugc">dev note</a>, some sites may be built in a way that fundamentally does not work with loading separate block styles on demand. For these sites, this plugin is available to retain the old behavior.

Load Combined Core Block Assets

Workaround for sites experiencing issues with WordPress 6.9's changed default behavior to load block styles on demand in classic themes.

Load Combined Core Block Assets vs Speed Optimizer – The All-In-One Performance-Boosting Plugin