Shopify total CSS payload and the Core Web Vitals
13.8% of audited sites (1,139) ship under 40 KB of CSS and pass LCP at 98% (1.1s median), whereas the 7.7% shipping over 160 KB drop to 93% (1.5s median).
46.6% of Shopify sites use 40 to 80 KB of CSS total CSS payload, and 98% of those sites have a good LCP, against 97% of all Shopify sites.
LCP pass rate
Sites with 40 to 80 KB of CSS total CSS payload have a good LCP most often: 98%, against 97% of all Shopify sites. Sites with over 160 KB of CSS CSS payload have it least often, at 93%.
Total CSS payload usage
40 to 80 KB of CSS is the most used: 46.6% of Shopify sites.
The four LCP phases
Across the four LCP sub-parts in Chrome's field data, the largest gap between 40 to 80 KB of CSS and over 160 KB of CSS sits in resource load delay: 563 ms median for 40 to 80 KB of CSS against 746 ms for over 160 KB of CSS. Overall median field LCP is 1.2s for 40 to 80 KB of CSS (TTFB 292 ms, load delay 563 ms, load duration 161 ms, render delay 270 ms) versus 1.5s for over 160 KB of CSS.
Total CSS payload per framework
On jQuery, 37% of sites use 80 to 160 KB of CSS total CSS payload, and 95% of jQuery sites have a good LCP, against 97% of all sites. On Vue, 50% of sites use 80 to 160 KB of CSS, and 97% of Vue sites have a good LCP.
Vue 933 sites80 to 160 KB 50%40 to 80 KB 30%Over 160 KB 15%97%
jQuery 3,153 sites80 to 160 KB 37%40 to 80 KB 36%Under 40 KB 16%Over 160 KB 11%95%Total CSS payload or the framework
Does the framework explain the total CSS payload difference?
On jQuery, 97% of sites with 40 to 80 KB of CSS total CSS payload have a good LCP, against 94% of jQuery sites with 80 to 160 KB of CSS. Within jQuery, sites with 40 to 80 KB of CSS have a good LCP more often. On Vue, 98% of sites with 40 to 80 KB of CSS total CSS payload have a good LCP, against 97% of Vue sites with 80 to 160 KB of CSS. Within Vue, sites with 40 to 80 KB of CSS and 80 to 160 KB of CSS have a good LCP about equally often.
Why stylesheet weight is a direct render blocker
External stylesheets block first paint until every CSS file in the document head is downloaded and parsed into the CSSOM. Across 1,139 sites (13.8%) under 40 KB of CSS, 98% pass field LCP at a 1.1s median, while the 7.7% (636) exceeding 160 KB fall to 93% good LCP (1.5s median).
Understanding total CSS payload
Keep total stylesheet transfer under 80 KB by purging unused utility classes, splitting template CSS per route, and removing legacy icon-font stylesheets. Across all audited sites, 13.8% stay under 40 KB (98% good LCP, 1.1s median) versus 7.7% above 160 KB (93% good LCP, 1.5s median).
By Arjen Karel · 8,246 crawled Shopify sites (3,818 with desktop Chrome field data, 8,244 sites with total CSS payload, October 2026). How we measured.