The State of Web Vitals

Layout shift causes on React sites

Element box growth (75.9%), sibling displacement (36.2%), web font reflow (20.2%), unsized media (2.4%), and late embed growth (0.7%) across 3,993 sites with recorded layout shifts.

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 →

20.2% of React sites use web font reflow layout shift causes, and 85% of those sites have a good CLS, against 92% of all React sites.

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 3,993 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
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CLS pass rate

Sites with web font reflow layout shift causes have a good CLS most often: 85%, against 92% of all React sites. Sites with sibling displacement shift causes have it least often, at 79%.

SitesGood, needs improvement, poor CLSMedian
All React sites5,48892%0.00
Web font swap text reflow 20.2%47185%0.00
Element box growth (box_grow) 75.9%1,85882%0.00
Displaced sibling element 36.2%87779%0.00
Unsized media expansion 2.4%6275%0.02
Late iframe / embed growth 0.7%1872%0.04
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 3,993 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
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Layout shift causes usage

Element box growth is the most used: 75.9% of React sites. Web font reflow is 20.2% of React sites.

Sites using each option (sites can use more than one) 3,993 sites
Element box growth (box_grow) 75.9% Displaced sibling element 36.2% Web font swap text reflow 20.2%
Element box growth (box_grow) 75.9% Displaced sibling element 36.2% Web font swap text reflow 20.2% Unsized media expansion 2.4% Late iframe / embed growth 0.7%
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 3,993 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
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Layout shift causes per platform

On WordPress, 80% of sites use element box growth layout shift causes, and 88% of WordPress sites have a good CLS, against 92% of all sites. On Wix, 61% of sites use element box growth, and 97% of Wix sites have a good CLS.

PlatformLayout shift causes on its sitesGood CLS
React sites with layout shift causes 3,993 sitesElement box growth (box_grow) 76%Displaced sibling element 36%Web font swap text reflow 20%92%
Wix 1,197 sitesElement box growth (box_grow) 61%Displaced sibling element 42%Web font swap text reflow 14%97%
WordPress 1,723 sitesElement box growth (box_grow) 80%Displaced sibling element 33%Web font swap text reflow 25%88%
Element box growth (box_grow) Displaced sibling element Web font swap text reflow Unsized media expansion Late iframe / embed growth
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 3,993 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
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Layout shift causes or the platform

Does the platform explain the layout shift causes difference?

On WordPress, 84% of sites with web font reflow layout shift causes have a good CLS, against 83% of WordPress sites with element box growth. Within WordPress, sites with web font reflow and element box growth have a good CLS about equally often. On Wix, 97% of sites with web font reflow layout shift causes have a good CLS, against 95% of Wix sites with element box growth. Within Wix, sites with web font reflow and element box growth have a good CLS about equally often.

How different DOM mutations translate into field CLS failures

Not all lab layout shifts hurt real users equally. Sites whose shifts come from web font swaps (20.2%) pass field CLS 85% of the time because line-height adjustments are small. Element box growth (75.9%, 82% good CLS) and displaced siblings (36.2%, 79% good CLS) cause moderate drops, while late iframe and embed growth (0.7%) pulls field CLS down to 72% (median CLS 0.04).

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 3,993 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
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Understanding layout shift causes

Eliminate late embed and banner growth first by reserving min-height containers for ad slots, promo bars, and third-party widgets. While 75.9% of shifting sites see element box growth (82% good CLS) and 20.2% see font swap reflow (85% good CLS), sites with unreserved iframe or embed growth (0.7%) pass field CLS only 72% of the time.

Go fix it Identify and fix CLS → CLS from images and media → Fix layout shift from auto-sizing images → Keep text visible during font load →
The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 5,488 with phone field data · 3,993 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
Related signals Layout shift count → Shift direction → Largest single shift → Shift concentration → By Arjen Karel · 9,570 crawled React sites (5,488 with phone Chrome field data, 3,993 sites with layout shift causes, October 2026) · How we measured