[wp-trac] [WordPress Trac] #64099: Load block styles on demand in classic themes via template enhancement output buffer

WordPress Trac noreply at wordpress.org
Tue Oct 21 05:59:57 UTC 2025


#64099: Load block styles on demand in classic themes via template enhancement
output buffer
----------------------------------------+--------------------------
 Reporter:  westonruter                 |       Owner:  westonruter
     Type:  enhancement                 |      Status:  closed
 Priority:  normal                      |   Milestone:  6.9
Component:  Script Loader               |     Version:
 Severity:  normal                      |  Resolution:  fixed
 Keywords:  has-patch needs-unit-tests  |     Focuses:  performance
----------------------------------------+--------------------------
Changes (by westonruter):

 * status:  accepted => closed
 * resolution:   => fixed


Comment:

 In [changeset:"61008" 61008]:
 {{{
 #!CommitTicketReference repository="" revision="61008"
 Script Loader: Load block styles on demand in classic themes via the
 template enhancement output buffer.

 * This applies in classic themes when a site has not opted out of the
 template enhancement buffer by filtering
 `wp_should_output_buffer_template_for_enhancement` off.
 * Both `should_load_separate_core_block_assets` and
 `should_load_block_assets_on_demand` are filtered on, as otherwise they
 are only enabled by default in block themes.
 * Any style enqueued after `wp_head` and printed via `print_late_styles()`
 will get hoisted up to be inserted right after the `wp-block-library`
 inline style in the `HEAD`.
 * The result is a >10% benchmarked improvement in LCP for core classic
 themes due to a ~100KB reduction in the amount of CSS unconditionally
 being served with every page load.

 Developed in https://github.com/WordPress/wordpress-develop/pull/10288

 Follow-up to [60936].

 Props sjapaget, westonruter, peterwilsoncc, dmsnell, mindctrl.
 See #43258.
 Fixes #64099.
 }}}

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/64099#comment:21>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform


More information about the wp-trac mailing list