Performance Chat Summary: 15 October 2024
Meeting agenda here and the full chat log is available beginning here on Slack.
Announcements
- Welcome to our new members of #core-performance
- WordPress 6.7 Beta 3 is October 15, with RC1 on October 22
- Reminder due to daylight savings, this meeting will shift to
- 16:00 UTC from October 29
Priority Items
- WordPress performance Trac tickets
- Current release (6.7)
- Future releases
- Performance Lab plugin (and other performance plugins)
- Active priority projects
WordPress Performance Trac Tickets
- There are currently 4 performance issues in 6.7 (bugs)
- @mukesh27 #61623 Is already committed by @sergeybiryukov part of 6.7 but some follow-up work needs to commit before RC, asked if @sergeybiryukov and @joemcgill have you had chance to review PR 7350 ?
Performance Lab Plugin (and other Performance Plugins)
- Performance Lab plugin and the following performance plugins:
- @westonruter Yesterday a major improvement to Optimization Detective was merged, Leverage URL metrics to reserve space for embeds to reduce CLS. On the surface this improves the Embed Optimizer plugin so that layout shifting caused by embeds (e.g. Tweets) is nearly eliminated. Under the covers, the improvements here change when a gathered URL metric is sent: instead of being sent after page load, it is sent later on when the page is left. This opens the door for capturing more metrics during the life of the page, including INP metrics. Additionally, this PR introduces a client-side extension framework using script modules.
- This PR was blocking several other improvements from moving forward as well, such as Add fetchpriority=low to occluded initial-viewport images, which is now ready for review.
- Another key PR to coincide with the WP 6.7 release is to use WP_HTML_Processor in Optimization Detective, which will leverage that new core feature. This will ensure that documents are properly parsed when they lack expected closing tags.
- Lastly, I’ve drafted Introduce OD_Element class to further improve the data model working with elements in URL Metrics.
- @swissspidy will attempt to expand OD for video poster images this week
- @joemcgill Last week, I updated https://github.com/WordPress/performance/issues/1511 with a summary of some technical discovery work from @mukesh27 and I, and shared that we’ll be picking up work on an implementation that uses the block context API to improve
sizescalculations based on layout context.
Active Priority Projects
Improving the calculation of image size attributes
- Updated shared above
Enable Client Side Modern Image Generation
- @swissspidy Slow progress at the moment, GB folks are busy with 6.7 so I don’t really get much feedback for any open PRs. Also, a key dependency I’m using for web workers was just deprecated, so now I need to consider alternatives
Enhance Onboarding Experience of Performance Lab Plugin
- @flixos90 This already predated last week’s meeting, but I don’t think I shared it here: In https://github.com/WordPress/performance/issues/1032#issuecomment-2384151984 I summarized some of the responses for the onboarding feedback form so far.
- I think the biggest priority based on the onboarding feedback is to make the feature/plugin activation work via AJAX. Because right now it results in a fresh page load, it means quickly activating multiple features is unnecessarily slow. It can sometimes even lead to weird errors if users click multiple buttons too fast (before the page reloaded)
- @flixos90 to open an issue for this
Open Floor
- @mukesh27 ran the benchmark for 6.7 Beta 3 and it shows the regression. For more details https://wordpress.slack.com/archives/C02KGN5K076/p1728969097396969
- @adamsilverstein I have been working on a colab to measure the impact of the Improved Responsive Images plugin / improved sizes work. I plan to keep expanding it, but results look promising so far
- @adamsilverstein At a high level, sites installing the plugin saw a 4 or 5 % improvement in CWV pass rates (mobile/desktop)
- @westonruter Any idea why this would be since only lazy-loaded images get auto-sizes? Which in theory wouldn’t be relevant for LCP? Are some of the lazy-loaded images with auto-sizes erroneously in the initial viewport, and so a smaller size of the image is getting downloaded and thus is reducing network contention for the LCP image?
- @joemcgill I’ve wondered the same thing. At least part of this could be that some of those sites are not lazy loading their LCP images properly. Some of that improvement could also be correlation with other Performance Lap improvements, since it’s hard to isolate causation in these queries
- @adamsilverstein some of it is correlation – for example when users install more than one optimization at a time; in the colab I’m also digging into some numbers like the Lighthouse “Properly size images” audit that are more directly impacted by the plugin. There we can also see the impact with less image optimization left to do in the audit after the plugin is installed
Our next chat will be held on Tuesday, October 22, 2024 at 15:00 UTC in the #core-performance channel in Slack.
