The State of Web Vitals

WordPress CLS shift concentration and the Core Web Vitals

Among sites recording lab layout shifts, 57.7% (25,913) concentrate 95% or more of their CLS into a single shift (89% good field CLS), while 18.2% suffer multiple compounding shifts (82% good field CLS).

Field data PhoneDesktopAll Scope All sites October 2026 edition · All devices field outcomes · WordPress sites only
WordPress Scoped to 63,295 sites out of 203,892 analyzed (cms) Compare with all sites →

57.7% of WordPress sites use a single dominant shift CLS shift concentration, and 89% of those sites have a good CLS, against 89% of all WordPress sites.

The State of Web Vitals · October 2026 · WordPress: 63,295 crawled sites · 60,855 with all devices field data · 44,905 sites with CLS shift concentrationBy Arjen Karel · corewebvitals.io/state-of-cwv
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CLS pass rate

Sites with a single dominant shift CLS shift concentration have a good CLS most often: 89%, against 89% of all WordPress sites. Sites with multiple compounding shifts shift concentration have it least often, at 82%.

SitesGood, needs improvement, poor CLSMedian
All WordPress sites60,85589%0.00
Single dominant shift (95%+) 57.7%24,88089%0.00
Mostly one shift (65-94%) 24.1%10,41784%0.01
Multiple compounding shifts (<65%) 18.2%7,88182%0.02
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · WordPress: 63,295 crawled sites · 60,855 with all devices field data · 44,905 sites with CLS shift concentrationBy Arjen Karel · corewebvitals.io/state-of-cwv
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CLS shift concentration usage

A single dominant shift is the most used: 57.7% of WordPress sites.

Single dominant shift (95%+) 57.7% Mostly one shift (65-94%) 24.1% Multiple compounding shifts (<65%) 18.2%
Single dominant shift (95%+) 57.7% Mostly one shift (65-94%) 24.1% Multiple compounding shifts (<65%) 18.2%
The State of Web Vitals · October 2026 · WordPress: 63,295 crawled sites · 60,855 with all devices field data · 44,905 sites with CLS shift concentrationBy Arjen Karel · corewebvitals.io/state-of-cwv
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CLS shift concentration per framework

jQuery sets the CLS shift concentration to a single dominant shift on 57% of its sites, and 89% of jQuery sites have a good CLS, against 89% of all sites.

FrameworkCLS shift concentration on its sitesGood CLS
WordPress sites with CLS shift concentration 44,905 sitesSingle dominant shift (95%+) 58%Mostly one shift (65-94%) 24%Multiple compounding shifts (<65%) 18%89%
jQuery 43,137 sitesSingle dominant shift (95%+) 57%Mostly one shift (65-94%) 24%Multiple compounding shifts (<65%) 19%89%
Vue 3,629 sitesSingle dominant shift (95%+) 57%Mostly one shift (65-94%) 25%Multiple compounding shifts (<65%) 18%89%
React 1,655 sitesSingle dominant shift (95%+) 55%Mostly one shift (65-94%) 25%Multiple compounding shifts (<65%) 19%85%
Single dominant shift (95%+) Mostly one shift (65-94%) Multiple compounding shifts (<65%)
The State of Web Vitals · October 2026 · WordPress: 63,295 crawled sites · 60,855 with all devices field data · 44,905 sites with CLS shift concentrationBy Arjen Karel · corewebvitals.io/state-of-cwv
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CLS shift concentration or the framework

Does the framework explain the CLS shift concentration difference?

On jQuery, 89% of sites with a single dominant shift CLS shift concentration have a good CLS, against 84% of jQuery sites with mostly one shift. Within jQuery, sites with a single dominant shift have a good CLS more often. On Vue, 89% of sites with a single dominant shift CLS shift concentration have a good CLS, against 85% of Vue sites with mostly one shift. Within Vue, sites with a single dominant shift have a good CLS more often.

One isolated layout jump versus cascading multi-element shifts

CLS concentration measures the ratio of the single largest layout shift to total lab CLS on pages with non-zero shift. Across 25,913 sites (57.7%) where one isolated element accounts for at least 95% of total CLS, 89% pass field CLS. When secondary shifts join in (24.1% at 65% to 94% concentration), good field CLS drops to 84%, and when shifts are spread across multiple compounding events (18.2%, 8,189 sites), good field CLS falls to 82%.

The State of Web Vitals · October 2026 · WordPress: 63,295 crawled sites · 60,855 with all devices field data · 44,905 sites with CLS shift concentrationBy Arjen Karel · corewebvitals.io/state-of-cwv
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Understanding CLS shift concentration

Use Chrome DevTools Performance layout shift attribution to fix the primary shifting element first, then lock down image aspect ratios and font fallbacks to stop secondary shifts. On WordPress, 57.7% of shifting pages have a single dominant shift (89% good CLS) versus 18.2% with multiple compounding shifts (82% good CLS).

Go fix it Scroll-triggered animations cause CLS → Layout shift caused by CSS transitions → Identify and fix CLS →
The State of Web Vitals · October 2026 · WordPress: 63,295 crawled sites · 60,855 with all devices field data · 44,905 sites with CLS shift concentrationBy Arjen Karel · corewebvitals.io/state-of-cwv
Related signals Largest single shift → Layout shift count → Shift direction → What shifted → By Arjen Karel · 63,295 crawled WordPress sites (60,855 with all devices Chrome field data, 44,905 sites with CLS shift concentration, October 2026) · How we measured