The State of Web Vitals

HTML document CDN on React sites

Direct from origin versus Cloudflare, Fastly, CloudFront, or Akamai: how serving the main HTML document through an edge CDN changes Time to First Byte (693 ms on Cloudflare vs 865 ms from origin) and Largest Contentful Paint.

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

47.4% of React sites have no an HTML edge CDN. Of the 52.6% that do, 70% use Fastly as, and 91% of those sites have a good LCP, against 79% of all React sites.

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 9,509 sites with an HTML edge CDNBy Arjen Karel · corewebvitals.io/state-of-cwv
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LCP pass rate

Sites with Fastly as an HTML edge CDN have a good LCP most often: 91%, against 79% of all React sites. Sites with Cloudflare as CDN have it least often, at 79%.

SitesGood, needs improvement, poor LCPMedian
All React sites1,97979%1.5s
Fastly 36.6%44391%1.2s
Amazon CloudFront 7.2%17482%1.5s
Cloudflare 7.6%23479%1.6s
Akamai 1.1%6275%1.7s
Direct from origin (no CDN) 47.4%1,06273%1.7s
Vercel Edge 0.1%450%1.6s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 9,509 sites with an HTML edge CDNBy Arjen Karel · corewebvitals.io/state-of-cwv
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An HTML edge CDN usage

52.6% of React sites use an HTML edge CDN, and 70% of those use Fastly as.

React sites with an HTML edge CDN 9,509 sites
Direct from origin (no CDN) 47.4% An HTML edge CDN 52.6%
Sites with an HTML edge CDN 5,005 sites
Fastly 69.6% Cloudflare 14.3% Amazon CloudFront 13.8%
Fastly 69.6% Cloudflare 14.3% Amazon CloudFront 13.8% Akamai 2.0% Vercel Edge 0.3%
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 9,509 sites with an HTML edge CDNBy Arjen Karel · corewebvitals.io/state-of-cwv
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Where an HTML CDN saves time: TTFB and the four LCP phases

Across the four LCP sub-parts in Chrome's field data, the largest gap between Fastly as and no sits in time to first byte (TTFB): 343 ms median for Fastly as against 865 ms for no. Overall median field LCP is 1.2s for Fastly as (TTFB 343 ms, load delay 465 ms, load duration 236 ms, render delay 140 ms) versus 1.8s for no.

Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
React sites with an HTML edge CDN 1,324703 ms413 ms192 ms413 mslab 429 ms1.6s
Direct from origin (no CDN) 752865 ms379 ms208 ms379 mslab 403 ms1.8s
Amazon CloudFront 107507 ms412 ms185 ms412 mslab 435 ms1.5s
Akamai 53814 ms424 ms284 ms424 mslab 407 ms1.7s
Cloudflare 169693 ms459 ms208 ms459 mslab 471 ms1.6s
Fastly 242343 ms465 ms236 ms465 mslab 444 ms1.2s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 9,509 sites with an HTML edge CDNBy Arjen Karel · corewebvitals.io/state-of-cwv
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An HTML edge CDN per platform

Wix sets the an HTML edge CDN to Fastly as on 58% of its sites, and 92% of Wix sites have a good LCP, against 79% of all sites.

PlatformAn HTML edge CDN on its sitesGood LCP
React sites with an HTML edge CDN 9,509 sitesDirect from origin (no CDN) 47%Fastly 37%79%
Wix 5,824 sitesFastly 58%Direct from origin (no CDN) 27%92%
WordPress 2,342 sitesDirect from origin (no CDN) 82%66%
Direct from origin (no CDN) Fastly Cloudflare Amazon CloudFront Akamai Vercel Edge
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 9,509 sites with an HTML edge CDNBy Arjen Karel · corewebvitals.io/state-of-cwv
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HTML edge CDN or the platform

Does the platform explain the an HTML edge CDN difference?

On Wix, 95% of sites with Fastly as an HTML edge CDN have a good LCP, against 85% of Wix sites with no. Within Wix, sites with Fastly as have a good LCP more often. On WordPress, 65% of sites with no an HTML edge CDN have a good LCP, against 69% of WordPress sites with Cloudflare as. Within WordPress, sites with no and Cloudflare as have a good LCP about equally often.

Why putting the HTML document on an edge CDN cuts TTFB

Static assets like images and scripts are easy to put on a CDN, but the browser cannot discover any of them until the main HTML document arrives. Routing the main domain through an edge network terminates DNS, TCP, and TLS at a point of presence near the visitor, and full-page HTML caching at the edge removes the origin server round trip entirely. In Chrome's field data, serving HTML through Cloudflare cuts median TTFB to 693 ms and Fastly cuts it to 343 ms, compared with 865 ms for documents served directly from the origin.

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 9,509 sites with an HTML edge CDNBy Arjen Karel · corewebvitals.io/state-of-cwv
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Understanding HTML document CDN delivery

Serve the main HTML document through an edge CDN and cache anonymous page views at the edge wherever possible. Across the dataset, 47.4% of sites still serve HTML directly from an origin server (73% good LCP, 865 ms median TTFB), while sites on Cloudflare (79% good LCP, 693 ms TTFB) and Fastly (91% good LCP, 343 ms TTFB) start rendering significantly earlier. Even when HTML cannot be cached publicly, edge TLS termination, HTTP/3 support, and tiered origin routing cut connection latency on every navigation.

Go fix it Configure Cloudflare for passing the Core Web Vitals → Time to First Byte → Free website cache warmer →
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 9,509 sites with an HTML edge CDNBy Arjen Karel · corewebvitals.io/state-of-cwv
Related signals ETag present → Requests via CDN → HTTP protocol mix → HTTP protocol → By Arjen Karel · 9,570 crawled React sites (1,979 with desktop Chrome field data, 9,509 sites with an HTML edge CDN, October 2026) · How we measured