The State of Web Vitals

Subresource CDN providers on React sites

Across audited sites, 99.9% (9,566) fetch requests from unfronted origin or custom hosts (84% good LCP), while 37.2% load assets via Cloudflare (77% good LCP), 74.5% via Amazon CloudFront (89% good LCP), and 68.0% via Fastly (91% good LCP, 1.2s median).

Field data PhoneDesktopAll Scope All sites October 2026 edition · Phone field outcomes · React sites only
React Scoped to 9,570 sites out of 210,902 analyzed (frameworks) Compare with all sites →

68.0% of React sites use Fastly subresource CDN distribution, and 91% of those sites have a good LCP, against 84% of all React sites.

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
1

LCP pass rate

Sites with Fastly subresource CDN distribution have a good LCP most often: 91%, against 84% of all React sites. Sites with Akamai subresource CDNs have it least often, at 71%.

SitesGood, needs improvement, poor LCPMedian
All React sites5,48884%1.4s
Fastly CDN 68.0%3,64491%1.2s
Amazon CloudFront 74.5%4,03189%1.3s
Direct origin / custom host 99.9%5,48484%1.4s
Netlify Edge 0.8%6179%2.3s
Cloudflare CDN 37.2%2,14977%1.7s
Vercel Edge Network 0.8%4376%1.4s
Akamai CDN 2.7%21271%1.9s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
2

Subresource CDN distribution usage

Origin/custom hosts is the most used: 99.9% of React sites. Fastly is 68.0% of React sites.

Sites using each option (sites can use more than one) 9,570 sites
Direct origin / custom host 99.9% Amazon CloudFront 74.5% Fastly CDN 68.0% Cloudflare CDN 37.2%
Direct origin / custom host 99.9% Amazon CloudFront 74.5% Fastly CDN 68.0% Cloudflare CDN 37.2% Akamai CDN 2.7% Netlify Edge 0.8% Vercel Edge Network 0.8%
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
3

LCP phase breakdown by CDN serving page subresources

Across the four LCP sub-parts in Chrome's field data, the largest gap between Fastly and Akamai sits in time to first byte (TTFB): 422 ms median for Fastly against 841 ms for Akamai. Overall median field LCP is 1.2s for Fastly (TTFB 422 ms, load delay 451 ms, load duration 115 ms, render delay 158 ms) versus 1.9s for Akamai.

Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
All React sites 4,169502 ms433 ms433 mslab 439 ms1.4s
Netlify Edge 501094 ms931 ms104 mslab 111 ms2.3s
Vercel Edge Network 31495 ms423 ms423 mslab 427 ms1.4s
Akamai CDN 181841 ms432 ms287 ms432 mslab 421 ms1.9s
Direct origin / custom host 4,166502 ms433 ms433 mslab 439 ms1.4s
Amazon CloudFront 3,064438 ms449 ms449 mslab 455 ms1.2s
Fastly CDN 2,775422 ms451 ms451 mslab 457 ms1.2s
Cloudflare CDN 1,636613 ms452 ms452 mslab 453 ms1.7s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
4

Subresource CDN distribution per platform

Wix sets the subresource CDN distribution to Fastly on 100% of its sites, and 94% of Wix sites have a good LCP, against 84% of all sites. WordPress sets the subresource CDN distribution to origin/custom hosts on 100% of its sites, and 63% of WordPress sites have a good LCP.

PlatformSubresource CDN distribution on its sitesGood LCP
All React sites 9,570 sitesDirect origin / custom host 100%Amazon CloudFront 75%Fastly CDN 68%Cloudflare CDN 37%84%
Wix 5,824 sitesFastly CDN 100%Direct origin / custom host 100%Amazon CloudFront 100%Cloudflare CDN 25%94%
WordPress 2,342 sitesDirect origin / custom host 100%Cloudflare CDN 52%Amazon CloudFront 27%Fastly CDN 15%63%
Direct origin / custom host Amazon CloudFront Fastly CDN Cloudflare CDN Akamai CDN Netlify Edge Vercel Edge Network
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
5

Subresource CDN or the platform

Does the platform explain the subresource CDN distribution difference?

On Wix, 94% of sites with Fastly subresource CDN distribution have a good LCP, against 94% of Wix sites with origin/custom hosts. Within Wix, sites with Fastly and origin/custom hosts have a good LCP about equally often. On WordPress, 60% of sites with Fastly subresource CDN distribution have a good LCP, against 63% of WordPress sites with origin/custom hosts. Within WordPress, sites with Fastly and origin/custom hosts have a good LCP about equally often.

Which CDN edges actually serve the images, scripts, and fonts on a page

Even when a site's main HTML document is served directly from an origin server, its subresources (images, scripts, fonts, third-party libraries) frequently traverse global CDNs. Across all audited sites, 37.2% (3,558) load subresources from Cloudflare (77% good LCP, 1.7s median), 74.5% (7,130) from Amazon CloudFront (89% good LCP), 68.0% (6,509) from Fastly (91% good LCP, 1.2s median), and 2.7% (263) from Akamai (71% good LCP).

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
6

Understanding subresource CDN providers

Serve static subresources (especially the LCP hero image, critical CSS, and web fonts) from the same edge CDN fronting your HTML document so requests coalesce over a single HTTP/2 or HTTP/3 connection. Across all audited sites, 37.2% fetch subresources from Cloudflare (77% good LCP) and 68.0% from Fastly (91% good LCP).

Go fix it Configure Cloudflare for passing the Core Web Vitals → Time to First Byte →
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
Related signals Last-Modified present → Uncompressed text responses → Cacheable responses → HTML size (kB) → By Arjen Karel · 9,570 crawled React sites (5,488 with phone Chrome field data, October 2026) · How we measured