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 (85% good LCP), while 37.2% load assets via Cloudflare (78% good LCP), 74.5% via Amazon CloudFront (90% good LCP), and 68.0% via Fastly (92% good LCP, 1.2s median).

Field data PhoneDesktopAll Scope All sites October 2026 edition · All devices 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 92% of those sites have a good LCP, against 85% of all React sites.

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 9,110 with all devices 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: 92%, against 85% of all React sites. Sites with Akamai subresource CDNs have it least often, at 71%.

SitesGood, needs improvement, poor LCPMedian
All React sites9,11085%1.4s
Fastly CDN 68.0%6,17492%1.2s
Amazon CloudFront 74.5%6,77390%1.3s
Direct origin / custom host 99.9%9,10685%1.4s
Netlify Edge 0.8%7484%2.1s
Cloudflare CDN 37.2%3,41678%1.7s
Vercel Edge Network 0.8%7477%1.6s
Akamai CDN 2.7%26071%1.9s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 9,110 with all devices 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 · 9,110 with all devices 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): 435 ms median for Fastly against 816 ms for Akamai. Overall median field LCP is 1.2s for Fastly (TTFB 435 ms, load delay 458 ms, load duration 139 ms, render delay 157 ms) versus 1.9s for Akamai.

Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
All React sites 6,740516 ms439 ms439 mslab 439 ms1.4s
Netlify Edge 581074 ms818 ms114 mslab 114 ms2.2s
Akamai CDN 218816 ms435 ms270 ms435 mslab 435 ms1.9s
Direct origin / custom host 6,737516 ms440 ms440 mslab 440 ms1.4s
Cloudflare CDN 2,532612 ms454 ms454 mslab 454 ms1.7s
Amazon CloudFront 5,009449 ms455 ms455 mslab 455 ms1.3s
Fastly CDN 4,554435 ms458 ms458 mslab 458 ms1.2s
Vercel Edge Network 50484 ms466 ms466 mslab 466 ms1.4s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 9,110 with all devices 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 85% of all sites. WordPress sets the subresource CDN distribution to origin/custom hosts on 100% of its sites, and 61% 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%85%
Wix 5,824 sitesDirect origin / custom host 100%Fastly CDN 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%61%
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 · 9,110 with all devices 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, 57% of sites with Fastly subresource CDN distribution have a good LCP, against 61% 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 (78% good LCP, 1.7s median), 74.5% (7,130) from Amazon CloudFront (90% good LCP), 68.0% (6,509) from Fastly (92% 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 · 9,110 with all devices 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 (78% good LCP) and 68.0% from Fastly (92% 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 · 9,110 with all devices 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 (9,110 with all devices Chrome field data, October 2026) · How we measured