Shopify HTTP Last-Modified headers and the Core Web Vitals
Whether responses carry Last-Modified validators.
100.0% of Shopify sites use Last-Modified headers Last-Modified cache validation, and 97% of those sites have a good LCP, against 97% of all Shopify sites.
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
1
LCP pass rate
Sites with Last-Modified headers Last-Modified cache validation have a good LCP most often: 97%, against 97% of all Shopify sites.
SitesGood, needs improvement, poor LCPMedian
All Shopify sites3,8181.3s
Last-Modified present 100.0%3,8181.3s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
2
Last-Modified cache validation usage
Last-Modified headers is the most used: 100.0% of Shopify sites.
Last-Modified present 100.0%
Last-Modified present 100.0%
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
3
LCP phase breakdown for sites with and without Last-Modified headers
Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
All Shopify sites 3,127630 mslab 620 ms1.3s
Last-Modified present 3,127630 mslab 620 ms1.3s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
4
Last-Modified cache validation per framework
jQuery sets the Last-Modified cache validation to Last-Modified headers on 100% of its sites, and 95% of jQuery sites have a good LCP, against 97% of all sites.
FrameworkLast-Modified cache validation on its sitesGood LCP
All Shopify sites 8,246 sitesLast-Modified present 100%97%
Vue 933 sitesLast-Modified present 100%97%
jQuery 3,153 sitesLast-Modified present 100%95% Last-Modified present
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
Related signals HTTP protocol → HTML size (kB) → Connection hints → HTML compression → By Arjen Karel · 8,246 crawled Shopify sites (3,818 with desktop Chrome field data, October 2026) · How we measured
By Arjen Karel · 8,246 crawled Shopify sites (3,818 with desktop Chrome field data, October 2026). How we measured.