The State of Web Vitals

First-party vs third-party stylesheets on React sites

99.9% of audited sites (9,557) serve first-party stylesheets (84% good LCP, 1.4s median), while the 44.7% (4,282) loading external third-party stylesheets drop to 79% good LCP (1.6s 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 →

99.9% of React sites use first-party stylesheets stylesheet origin (first-party vs third-party), and 84% 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 data · 9,569 sites with stylesheet origin (first-party vs third-party)By Arjen Karel · corewebvitals.io/state-of-cwv
1

LCP pass rate

Sites with first-party stylesheets stylesheet origin (first-party vs third-party) have a good LCP most often: 84%, against 84% of all React sites. Sites with third-party stylesheets CSS origin have it least often, at 79%.

SitesGood, needs improvement, poor LCPMedian
All React sites5,48884%1.4s
First-party stylesheets 99.9%5,48184%1.4s
Third-party stylesheets 44.7%2,57979%1.6s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 9,569 sites with stylesheet origin (first-party vs third-party)By Arjen Karel · corewebvitals.io/state-of-cwv
2

Stylesheet origin (first-party vs third-party) usage

First-party stylesheets is the most used: 99.9% of React sites.

Sites using each option (sites can use more than one) 9,569 sites
First-party stylesheets 99.9% Third-party stylesheets 44.7%
First-party stylesheets 99.9% Third-party stylesheets 44.7%
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 9,569 sites with stylesheet origin (first-party vs third-party)By Arjen Karel · corewebvitals.io/state-of-cwv
3

LCP phase breakdown for first-party and third-party stylesheets

Across the four LCP sub-parts in Chrome's field data, the largest gap between first-party stylesheets and third-party stylesheets sits in time to first byte (TTFB): 502 ms median for first-party stylesheets against 565 ms for third-party stylesheets. Overall median field LCP is 1.4s for first-party stylesheets (TTFB 502 ms, load delay 433 ms, load duration 131 ms, render delay 180 ms) versus 1.6s for third-party stylesheets.

Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
React sites with stylesheet origin (first-party vs third-party) 4,168502 ms433 ms180 ms433 mslab 439 ms1.4s
First-party stylesheets 4,164502 ms433 ms180 ms433 mslab 439 ms1.4s
Third-party stylesheets 1,955565 ms454 ms196 ms454 mslab 457 ms1.6s
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 data · 9,569 sites with stylesheet origin (first-party vs third-party)By Arjen Karel · corewebvitals.io/state-of-cwv
4

Stylesheet origin (first-party vs third-party) per platform

Wix sets the stylesheet origin (first-party vs third-party) to first-party stylesheets on 100% of its sites, and 94% of Wix sites have a good LCP, against 84% of all sites.

PlatformStylesheet origin (first-party vs third-party) on its sitesGood LCP
React sites with stylesheet origin (first-party vs third-party) 9,569 sitesFirst-party stylesheets 100%Third-party stylesheets 45%84%
Wix 5,824 sitesFirst-party stylesheets 100%Third-party stylesheets 34%94%
WordPress 2,342 sitesFirst-party stylesheets 100%Third-party stylesheets 62%63%
First-party stylesheets Third-party stylesheets
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 9,569 sites with stylesheet origin (first-party vs third-party)By Arjen Karel · corewebvitals.io/state-of-cwv
5

Stylesheet origin or the platform

Does the platform explain the stylesheet origin (first-party vs third-party) difference?

On Wix, 94% of sites with first-party stylesheets stylesheet origin (first-party vs third-party) have a good LCP, against 93% of Wix sites with third-party stylesheets. Within Wix, sites with first-party stylesheets and third-party stylesheets have a good LCP about equally often. On WordPress, 63% of sites with first-party stylesheets stylesheet origin (first-party vs third-party) have a good LCP, against 59% of WordPress sites with third-party stylesheets. Within WordPress, sites with first-party stylesheets and third-party stylesheets have a good LCP about equally often.

How cross-origin CSS files add DNS and TLS round-trips to the critical rendering path

Because external stylesheets block rendering by default, fetching a CSS file from a third-party domain (such as fonts.googleapis.com, cdnjs, or a widget CDN) stalls first paint behind a fresh DNS lookup, TCP handshake, and TLS negotiation. Across 9,557 sites (99.9%) with first-party CSS, good LCP is 84% (1.4s median), whereas across 4,282 sites (44.7%) with third-party CSS, good LCP drops to 79% (1.6s median).

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 9,569 sites with stylesheet origin (first-party vs third-party)By Arjen Karel · corewebvitals.io/state-of-cwv
6

Understanding first-party vs third-party stylesheets

Copy external font and icon stylesheets (Google Fonts, Font Awesome, Bootstrap CDN) into your own build pipeline or origin server so every render-blocking CSS file shares the primary HTTP/2 or HTTP/3 connection. Across all audited sites, 99.9% use first-party CSS (84% good LCP) and 44.7% load third-party CSS (79% good LCP).

Go fix it Self-host Google Fonts → Eliminate render-blocking resources →
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 9,569 sites with stylesheet origin (first-party vs third-party)By Arjen Karel · corewebvitals.io/state-of-cwv
Related signals Bytes by resource type → Image source mix → Stylesheet loading mix → Uses @import → By Arjen Karel · 9,570 crawled React sites (5,488 with phone Chrome field data, 9,569 sites with stylesheet origin (first-party vs third-party), October 2026) · How we measured