The State of Web Vitals

Subresource network protocols (HTTP/2, HTTP/3, HTTP/1.1) and the Core Web Vitals

HTTP/2 (92.5%), HTTP/3 QUIC (70.9%), and legacy HTTP/1.1 (68.2%) across all page subrequests: how connection protocols move Largest Contentful Paint.

Field data PhoneDesktopAll Scope All sites October 2026 edition · Phone field outcomes

92.5% of sites use HTTP/2 subresource network protocols, and 81% of those sites have a good LCP, against 82% of all sites.

The State of Web Vitals · October 2026 · 210,902 crawled sites · 126,761 with phone field data · 206,252 sites with subresource network protocolsBy Arjen Karel · corewebvitals.io/state-of-cwv
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LCP pass rate

Sites with HTTP/2 subresource network protocols have a good LCP most often: 81%, against 82% of all sites. Sites with HTTP/3 network protocols have it least often, at 81%.

SitesGood, needs improvement, poor LCPMedian
All sites126,76182%1.6s
HTTP/2 (h2) 92.5%118,59081%1.6s
HTTP/1.1 68.2%87,05381%1.6s
HTTP/3 (QUIC / h3) 70.9%89,28481%1.6s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · 210,902 crawled sites · 126,761 with phone field data · 206,252 sites with subresource network protocolsBy Arjen Karel · corewebvitals.io/state-of-cwv
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Subresource network protocols usage

HTTP/2 is the most used: 92.5% of sites.

Sites using each option (sites can use more than one) 206,252 sites
HTTP/2 (h2) 92.5% HTTP/3 (QUIC / h3) 70.9% HTTP/1.1 68.2%
HTTP/2 (h2) 92.5% HTTP/3 (QUIC / h3) 70.9% HTTP/1.1 68.2%
The State of Web Vitals · October 2026 · 210,902 crawled sites · 126,761 with phone field data · 206,252 sites with subresource network protocolsBy Arjen Karel · corewebvitals.io/state-of-cwv
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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/2 and HTTP/3 sits in resource load delay: 339 ms median for HTTP/2 against 362 ms for HTTP/3. Overall median field LCP is 1.6s for HTTP/2 (TTFB 656 ms, load delay 339 ms, load duration 152 ms, render delay 238 ms) versus 1.6s for HTTP/3.

Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
Sites with subresource network protocols 92,464650 ms336 ms236 ms336 mslab 326 ms1.6s
HTTP/2 (h2) 87,044656 ms339 ms238 ms339 mslab 329 ms1.6s
HTTP/3 (QUIC / h3) 66,472654 ms362 ms244 ms362 mslab 353 ms1.6s
HTTP/1.1 64,714632 ms371 ms242 ms371 mslab 361 ms1.6s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · 210,902 crawled sites · 126,761 with phone field data · 206,252 sites with subresource network protocolsBy Arjen Karel · corewebvitals.io/state-of-cwv
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Understanding subresource network protocols

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, 92.5% load subresources over HTTP/2 (81% good LCP), 70.9% negotiate HTTP/3 on at least one origin (81% good LCP), and 68.2% still make at least one legacy HTTP/1.1 request (81% good LCP).

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 (68.2% 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.

Go fix it Third-party domains → Configure Cloudflare for passing the Core Web Vitals →
The State of Web Vitals · October 2026 · 210,902 crawled sites · 126,761 with phone field data · 206,252 sites with subresource network protocolsBy Arjen Karel · corewebvitals.io/state-of-cwv
Platform & Framework Takeaways

How subresource network protocols plays out per platform

What the field data shows when you isolate a single CMS or framework.

WordPress 65,509 sites
97% / 77% / 62% H2 / H3 / HTTP/1.1 subresources

WordPress sites fetch subresources over HTTP/2 on 96.9%, HTTP/3 on 77.0%, and HTTP/1.1 on 62.0%.

Across 65,509 WordPress sites, 96.9% fetch subresources over HTTP/2 (69% good LCP), 77.0% over HTTP/3, and 62.0% include at least one HTTP/1.1 request (67% good LCP).

Read the WordPress network protocol breakdown →
Shopify 8,573 stores
98% H3 / 100% H2 edge subresource multiplexing (95% good LCP)

Shopify storefronts load subresources over HTTP/3 (98%), HTTP/2 (99.5%), and HTTP/1.1 (99.9%).

Across Shopify storefronts, 98.2% fetch subresources over HTTP/3, 99.5% over HTTP/2, and 99.9% include HTTP/1.1 subresource requests (95% good LCP overall).

Read the Shopify network protocol breakdown →
React & Next.js 9,570 sites
90.7% negotiate HTTP/3 (85% good LCP)

React sites reach 98.8% HTTP/2 and 90.7% HTTP/3 subresource adoption (85% good LCP).

Across 9,570 React sites, 98.8% serve subresources over HTTP/2 and 90.7% serve subresources over HTTP/3 (85% good LCP).

Related signals Connection hints → Main CDN → HTTP protocol → HTML compression → By Arjen Karel · 210,902 crawled sites (126,761 with phone Chrome field data, 206,252 sites with subresource network protocols, October 2026) · How we measured