Shopify layout shift causes (CLS attribution) and field CLS

Element box growth (79.8%), sibling displacement (36.1%), web font reflow (19.2%), unsized media (2.8%), and late embed growth (0.4%) across 5,389 sites with recorded layout shifts.

Field data PhoneDesktopAll Scope All sites October 2026 edition · Phone field outcomes · Shopify sites only
Shopify Scoped to 8,248 sites out of 203,892 analyzed (cms) Compare with all sites →

79.8% of Shopify sites use element box growth layout shift causes, and 91% of those sites have a good CLS, against 94% of all Shopify sites.

The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 5,825 with phone field data · 5,389 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
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CLS pass rate

Sites with element box growth layout shift causes have a good CLS most often: 91%, against 94% of all Shopify sites. Sites with sibling displacement shift causes have it least often, at 90%.

SitesGood, needs improvement, poor CLSMedian
All Shopify sites5,82594%0.00
Element box growth (box_grow) 79.8%3,08591%0.00
Web font swap text reflow 19.2%72791%0.00
Unsized media expansion 2.8%11691%0.01
Displaced sibling element 36.1%1,41590%0.00
Late iframe / embed growth 0.4%1669%0.04
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 5,825 with phone field data · 5,389 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: 79.8% of Shopify sites.

Sites using each option (sites can use more than one) 5,389 sites
Element box growth (box_grow) 79.8% Displaced sibling element 36.1% Web font swap text reflow 19.2%
Element box growth (box_grow) 79.8% Displaced sibling element 36.1% Web font swap text reflow 19.2% Unsized media expansion 2.8% Late iframe / embed growth 0.4%
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 5,825 with phone field data · 5,389 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
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Layout shift causes per framework

jQuery sets the layout shift causes to element box growth on 84% of its sites, and 91% of jQuery sites have a good CLS, against 94% of all sites.

FrameworkLayout shift causes on its sitesGood CLS
Shopify sites with layout shift causes 5,389 sitesElement box growth (box_grow) 80%Displaced sibling element 36%Web font swap text reflow 19%94%
jQuery 2,327 sitesElement box growth (box_grow) 84%Displaced sibling element 35%Web font swap text reflow 21%91%
Vue 669 sitesElement box growth (box_grow) 84%Displaced sibling element 39%Web font swap text reflow 18%90%
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 · Shopify: 8,246 crawled sites · 5,825 with phone field data · 5,389 sites with layout shift causesBy Arjen Karel · corewebvitals.io/state-of-cwv
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Layout shift causes or the framework

Does the framework explain the layout shift causes difference?

On jQuery, 88% of sites with element box growth layout shift causes have a good CLS, against 86% of jQuery sites with sibling displacement. Within jQuery, sites with element box growth and sibling displacement have a good CLS about equally often. On Vue, 88% of sites with element box growth layout shift causes have a good CLS, against 87% of Vue sites with sibling displacement. Within Vue, sites with element box growth and sibling displacement 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 (19.2%) pass field CLS 91% of the time because line-height adjustments are small. Element box growth (79.8%, 91% good CLS) and displaced siblings (36.1%, 90% good CLS) cause moderate drops, while late iframe and embed growth (0.4%) pulls field CLS down to 69% (median CLS 0.04).

The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 5,825 with phone field data · 5,389 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 79.8% of shifting sites see element box growth (91% good CLS) and 19.2% see font swap reflow (91% good CLS), sites with unreserved iframe or embed growth (0.4%) pass field CLS only 69% of the time.

The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 5,825 with phone field data · 5,389 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 · 8,246 crawled Shopify sites (5,825 with phone Chrome field data, 5,389 sites with layout shift causes, October 2026) · How we measured