WordPress stylesheet loading and placement and the Core Web Vitals

Sites with inline <style> blocks stylesheet loading and placement have a good LCP most often: 70%, against 70% of all WordPress sites. Sites with <body> stylesheets CSS loading have it least often, at 62%.

Sites with render-blocking <head> stylesheets stylesheet loading and placement have a good CLS most often: 89%, against 89% of all WordPress sites. Sites with <body> stylesheets CSS loading have it least often, at 87%.

Inline <style> blocks is the most used: 99.4% of WordPress sites.

Across the four LCP sub-parts in Chrome's field data, the largest gap between inline <style> blocks and <body> stylesheets sits in time to first byte (TTFB): 1129 ms median for inline <style> blocks against 1277 ms for <body> stylesheets. Overall median field LCP is 1.9s for inline <style> blocks (TTFB 1129 ms, load delay 341 ms, load duration 166 ms, render delay 235 ms) versus 2.2s for <body> stylesheets.

Across the four LCP sub-parts in Chrome's field data, the largest gap between inline <style> blocks and <body> stylesheets sits in time to first byte (TTFB): 1129 ms median for inline <style> blocks against 1277 ms for <body> stylesheets. Overall median field LCP is 1.9s for inline <style> blocks (TTFB 1129 ms, load delay 341 ms, load duration 166 ms, render delay 235 ms) versus 2.2s for <body> stylesheets.

Alpine sets the stylesheet loading and placement to inline <style> blocks on 100% of its sites, and 80% of Alpine sites have a good LCP, against 70% of all sites. Vue sets the stylesheet loading and placement to render-blocking <head> stylesheets on 100% of its sites, and 68% of Vue sites have a good LCP.

Alpine sets the stylesheet loading and placement to inline <style> blocks on 100% of its sites, and 90% of Alpine sites have a good CLS, against 89% of all sites. Vue sets the stylesheet loading and placement to render-blocking <head> stylesheets on 100% of its sites, and 89% of Vue sites have a good CLS.

FrameworkStylesheet loading and placement on its sitesGood LCP

WordPress sites with stylesheet loading and placement 63,291 sitesInline <style> blocks 99%Render-blocking in <head> 99%Stylesheets inside <body> 36%Non-blocking in <head> (preload / media) 21%70%

Alpine 380 sitesInline <style> blocks 100%Render-blocking in <head> 98%Stylesheets inside <body> 29%Non-blocking in <head> (preload / media) 16%80%

jQuery 60,310 sitesInline <style> blocks 99%Render-blocking in <head> 99%Stylesheets inside <body> 37%Non-blocking in <head> (preload / media) 21%69%

Vue 4,844 sitesRender-blocking in <head> 100%Inline <style> blocks 100%Stylesheets inside <body> 39%Non-blocking in <head> (preload / media) 18%68%

React 2,233 sitesInline <style> blocks 100%Render-blocking in <head> 99%Stylesheets inside <body> 46%Non-blocking in <head> (preload / media) 35%61%

Inline <style> blocks Render-blocking in <head> Stylesheets inside <body> Non-blocking in <head> (preload / media)

Does the framework explain the stylesheet loading and placement difference?

Almost every site with inline <style> blocks stylesheet loading and placement is a jQuery site, and almost every jQuery site has inline <style> blocks stylesheet loading and placement, so the data can't tell inline <style> blocks stylesheet loading and placement and jQuery apart. On Vue, 68% of sites with inline <style> blocks stylesheet loading and placement have a good LCP, against 68% of Vue sites with render-blocking <head> stylesheets. Within Vue, sites with inline <style> blocks and render-blocking <head> stylesheets have a good LCP about equally often. On React, 61% of sites with inline <style> blocks stylesheet loading and placement have a good LCP, against 61% of React sites with render-blocking <head> stylesheets. Within React, sites with inline <style> blocks and render-blocking <head> stylesheets have a good LCP about equally often.

Almost every site with render-blocking <head> stylesheets stylesheet loading and placement is a jQuery site, and almost every jQuery site has render-blocking <head> stylesheets stylesheet loading and placement, so the data can't tell render-blocking <head> stylesheets stylesheet loading and placement and jQuery apart. On Vue, 89% of sites with render-blocking <head> stylesheets stylesheet loading and placement have a good CLS, against 89% of Vue sites with inline <style> blocks. Within Vue, sites with render-blocking <head> stylesheets and inline <style> blocks have a good CLS about equally often. On React, 85% of sites with render-blocking <head> stylesheets stylesheet loading and placement have a good CLS, against 85% of React sites with inline <style> blocks. Within React, sites with render-blocking <head> stylesheets and inline <style> blocks have a good CLS about equally often.

Why <link rel="stylesheet"> inside <body> hurts LCP and triggers late style recalculation

Standard <link rel="stylesheet"> tags in <head> (98.9% of sites, 62,581) block first paint until downloaded (70% good LCP, 1.9s median), while inline <style> blocks (99.4%) reach 70% good LCP and non-blocking <head> stylesheets (20.7%) reach 63% good LCP (2.1s median). Scattering <link rel="stylesheet"> tags inside <body> (35.7% of sites, 22,615) forces late parser pauses and mid-render style passes, dropping good LCP to 62% (2.2s median).