Performance Year-End Chat Summary: 23 December 2025
The full chat log is available beginning here on Slack.
View Transitions to Core
- @westonruter kicked off the discussion by referencing plans to graduate the View Transitions plugin into core for WordPress 7.0, noting it pairs well with the admin refresh and introduces theme support for configuration.
- @mikewpbullet raised concerns about potential clashes with plugins or custom code and suggested a UI checkbox or update splash screen guidance, while @schmitzoide proposed a general “Activate Advanced Features” checkbox.
- @adamsilverstein noted performance plugins could add controls.
- @westonruter clarified that sites could opt out via code toggles like filters or theme support, aligning with WordPress philosophy of decisions over options.
Speculative Loading and Caching Enhancements
- @westonruter highlighted ticket #64066 to shift default eagerness from conservative to moderate when caching is detected, aiding View Transitions by reducing link click delays.
- @mikewpbullet raised concerns about page caching rarely helping admin performance and noted that server-side caching via nginx or Varnish often runs without WordPress plugins that Site Health could detect.
- @westonruter explained that core’s Site Health test already accounts for proxy caches beyond just plugins and remains extensible for improvement.
- @adamsilverstein acknowledged that comprehensive coverage is impossible but emphasized WordPress’s advantage in rendering detection rules dynamically.
- @schmitzoide asked whether Site Health could diagnose performance issues.
- @westonruter added that Performance Lab includes additional tests for excessive blocking scripts and styles.
- @westonruter responded to @mikewpbullet‘s earlier admin concerns with two ideas: enabling bfcache in the admin for smooth back/forward transitions #63636, and considering speculative loading for admin menu items on sites with object caching enabled.
- @mikewpbullet raised concerns that users may not want cached admin pages when hitting back, and that object caching is unlikely to help with page load times in admin where slowness comes from 3rd party background requests.
Admin and Dashboard Performance
- @adamsilverstein shared that tackling the Dashboard landing page is a priority for the new year and mentioned an existing performance ticket. @westonruter later identified ticket #55344 and suggested the Dashboard could leverage preload links for commonly-used resources like the edit post screen assets.
- @westonruter connected this to ticket #57548 about retiring script and style concatenation in wp-admin, explaining the benefit would be effective preloading but noting that concatenation might still offer better performance without a primed cache, which requires benchmarking. This discussion led to exploring Compression Dictionaries, a newer capability that @westonruter explained allows browsers to reuse intersecting portions of different concatenated bundles.
- @mikewpbullet questioned the need given server-side Brotli compression already exists.
- @westonruter clarified this isn’t about PHP-based gzip but about the new compression dictionary transport standard that enables reusing cached bundle portions across different pages, particularly beneficial for block themes enqueue block styles on-demand based on page content, and in WordPress 6.9 this also applies to classic themes, so compression dictionaries would allow concatenating these varying bundles while enabling browsers to cache and reuse individual styles across pages with different bundles, significantly reducing CSS downloads for both logged-in and logged-out users.
Roadmap and Future Planning
- @schmitzoide asked about the team’s roadmap. @westonruter linked to the 2024 roadmap and explained this meeting serves to shape 2026 priorities, noting they’ll likely use milestoned Trac tickets rather than a full roadmap post given fewer active contributors currently.
- @schmitzoide asked about graduating additional Performance Lab features and shared plans to propose ideas from block theme optimization work via repository tickets. @adamsilverstein encouraged opening issues for any PerfNow conference ideas worth experimenting with in the plugin.
- @sirlouen asked about integrating performance testing activities similar to Gutenberg’s approach, including GitHub Actions tagging and handbook expansion. @westonruter welcomed aligning testing strategies with other core teams in the new year.
Our next chat will be held on Tuesday, December 30, 2025 at 16:00 UTC in the #core-performance channel in Slack.
