Shopify subresource network protocols and the Core Web Vitals

HTTP/2 (99.6%), HTTP/3 QUIC (99.9%), and legacy HTTP/1.1 (99.9%) across all page subrequests: how connection protocols move Largest Contentful Paint.

Field data PhoneDesktopAll Scope All sites October 2026 edition · Desktop field outcomes · Shopify sites only
Shopify Scoped to 8,248 sites out of 203,892 analyzed (cms) Compare with all sites →

99.9% of Shopify sites use HTTP/3 subresource network protocols, 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 HTTP/3 subresource network protocols have a good LCP most often: 97%, against 97% of all Shopify sites. Sites with HTTP/2 network protocols have it least often, at 97%.

SitesGood, needs improvement, poor LCPMedian
All Shopify sites3,81897%1.3s
HTTP/3 (QUIC / h3) 99.9%3,81797%1.3s
HTTP/1.1 99.9%3,81497%1.3s
HTTP/2 (h2) 99.6%3,81197%1.3s
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

Subresource network protocols usage

HTTP/3 is the most used: 99.9% of Shopify sites.

Sites using each option (sites can use more than one) 8,246 sites
HTTP/3 (QUIC / h3) 99.9% HTTP/1.1 99.9% HTTP/2 (h2) 99.6%
HTTP/3 (QUIC / h3) 99.9% HTTP/1.1 99.9% HTTP/2 (h2) 99.6%
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

How subresource network protocols affect the four LCP phases

Across the four LCP sub-parts in Chrome's field data, the largest gap between HTTP/3 and HTTP/2 sits in time to first byte (TTFB): 305 ms median for HTTP/3 against 305 ms for HTTP/2. Overall median field LCP is 1.3s for HTTP/3 (TTFB 305 ms, load delay 630 ms, load duration 152 ms, render delay 304 ms) versus 1.3s for HTTP/2.

Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
All Shopify sites 3,127305 ms630 ms304 ms630 mslab 620 ms1.3s
HTTP/2 (h2) 3,121305 ms630 ms304 ms630 mslab 620 ms1.3s
HTTP/3 (QUIC / h3) 3,126305 ms630 ms304 ms630 mslab 620 ms1.3s
HTTP/1.1 3,123305 ms630 ms304 ms630 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

Subresource network protocols per framework

jQuery sets the subresource network protocols to HTTP/3 on 100% of its sites, and 95% of jQuery sites have a good LCP, against 97% of all sites. Vue sets the subresource network protocols to HTTP/1.1 on 100% of its sites, and 97% of Vue sites have a good LCP.

FrameworkSubresource network protocols on its sitesGood LCP
All Shopify sites 8,246 sitesHTTP/3 (QUIC / h3) 100%HTTP/1.1 100%HTTP/2 (h2) 100%97%
Vue 933 sitesHTTP/1.1 100%HTTP/2 (h2) 100%HTTP/3 (QUIC / h3) 100%97%
jQuery 3,153 sitesHTTP/3 (QUIC / h3) 100%HTTP/2 (h2) 100%HTTP/1.1 100%95%
HTTP/3 (QUIC / h3) HTTP/1.1 HTTP/2 (h2)
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
5

Subresource network protocols or the framework

Does the framework explain the subresource network protocols difference?

On jQuery, 95% of sites with HTTP/3 subresource network protocols have a good LCP, against 95% of jQuery sites with HTTP/1.1. Within jQuery, sites with HTTP/3 and HTTP/1.1 have a good LCP about equally often. On Vue, 97% of sites with HTTP/3 subresource network protocols have a good LCP, against 97% of Vue sites with HTTP/1.1. Within Vue, sites with HTTP/3 and HTTP/1.1 have a good LCP about equally often.

Why most pages mix HTTP/2, HTTP/3, and HTTP/1.1 in a single load

While a page's HTML document uses a single connection, its subresources come from first-party CDNs, font hosts, and third-party scripts. Across 189,798 sites, 99.6% load subresources over HTTP/2 (97% good LCP), 99.9% negotiate HTTP/3 on at least one origin (97% good LCP), and 99.9% still make at least one legacy HTTP/1.1 request (97% good LCP).

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
6

Understanding subresource network protocols

Serve all first-party static assets over HTTP/2 and HTTP/3 via a modern CDN, and audit third-party scripts or unproxied asset hosts that still fall back to HTTP/1.1 (99.9% of sites). HTTP/1.1 origins cannot multiplex concurrent requests over a single connection, adding head-of-line blocking when multiple assets share that domain.

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 Connection hints → Main CDN → HTTP protocol → HTML compression → By Arjen Karel · 8,246 crawled Shopify sites (3,818 with desktop Chrome field data, October 2026) · How we measured