Load Combined Core Block Assets

Description

This is a temporary workaround for sites experiencing any issues with WordPress 6.9’s new ability to load block styles on demand in classic themes, for example #64354.

If running a classic theme (i.e. not a block theme), it filters should_load_separate_core_block_assets to be false. 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 6.9.1. At any time, you can test whether any issues remain by adding ?should_load_separate_core_block_assets=true to any frontend URL; this restores the default behavior in WP 6.9.

This workaround is 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 wp-block-library stylesheet. Loading separate block styles on demand reduces the amount of CSS which should improve page load time.

Installation

Automatic

  1. Visit Plugins > Add New in the WordPress Admin.
  2. Search for Load Combined Core Block Assets.
  3. Install and activate the Load Combined Core Block Assets plugin.

You may also install and update via Git Updater using the plugin’s GitHub URL.

Manual

  1. Download the plugin ZIP either from WordPress.org or from GitHub. Alternatively, if you have a local clone of the repo, run npm run plugin-zip.
  2. Visit Plugins > Add New Plugin in the WordPress Admin.
  3. Click Upload Plugin.
  4. Select the load-combined-core-block-assets.zip file on your system from step 1 and click Install Now.
  5. Click the Activate Plugin button.

Reviews

December 15, 2025
We built and maintain a hybrid classic/headless WordPress website for a national client. A number of our frontend components (CoreButton, CoreMediaText, etc.) tap into WordPress core editor classnames, props, and critically, CSS rulesets, to provide our client the flexibility they expect when editing blocks and posts.After updating to WordPress 6.9, these components failed to render as expected. Our investigation led us to the post on wordpress-6-9-hotfixes, and subsequently, this plugin. Thankfully, installing this plugin resolved the issue.Thanks to @westonruter for taking the time to publish this hot-fix.
December 10, 2025
This little plugin is a life saver for anyone running classic themes on WordPress 6.9+. In my case it instantly fixed broken layouts caused by the new “block styles on demand” system clashing with a 3rd party WooCommerce plugin on a Genesis site. If your front end suddenly looks off after updating to WordPress 6.9, install this first before you start tearing your frontend apart!
Read all 4 reviews

Contributors & Developers

“Load Combined Core Block Assets” is open source software. The following people have contributed to this plugin.

Contributors

“Load Combined Core Block Assets” has been translated into 2 locales. Thank you to the translators for their contributions.

Translate “Load Combined Core Block Assets” into your language.

Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.

Changelog

1.0.0

  • Escape translated message in HTML comment for extra hardening.

0.1.0

  • Initial release.