The State of Web Vitals

Shift concentration

How concentrated the shifting is: largest shift over total shift.

Field data PhoneDesktopAll Scope All sites Q1 2026 edition · All devices field outcomes
Metric LCP INP CLS
1

At a glance the headline numbers for Shift concentration

How concentrated the shifting is: largest shift over total shift.

1
on the typical site
half of sites sit at or below
1
1 in 4 sites exceed this
the top quarter
6
the heaviest 1%
the long tail
63,444
sites measured
all-device field data

On the typical site, the largest single shift causes 1 of all layout shift.

The State of Web Vitals · Q1 2026 · 94,910 sites · all devices field datacorewebvitals.io/state-of-cwv
2

Distribution & median CLS site count and median CLS at each level of shift concentration

0.00 0.04 0.08 0.11 0.15
0.1
0 21102 42204
0.2–0.252 0.252–0.319 0.319–0.402 0.402–0.507 0.507–0.64 0.64–0.808 0.808–1.02 1.02–1.29 1.29–1.62 1.62–2.05 >p98
Good (≤0.1) Needs improvement Poor (>0.25) Site count
The State of Web Vitals · Q1 2026 · 94,910 sites · all devices field datacorewebvitals.io/state-of-cwv
3

Passing CLS by shift concentration which level passes the CLS most often

Shift concentrationSitesPassing CLSCLS
0.2–0.252 317 89% 0.01
0.252–0.319 555 85% 0.01
0.319–0.402 1,434 81% 0.02
0.402–0.507 3,602 78% 0.02
0.507–0.64 6,003 81% 0.02
0.64–0.808 7,389 82% 0.01
0.808–1.02 42,204 88% 0.00
1.02–1.29 248 73% 0.03
1.29–1.62 216 79% 0.02
1.62–2.05 207 71% 0.03
>p98 1,269 72% 0.03
Good Needs Improvement Poor Faded rows: under 100 sites

Shift concentration 1.0. p75 1. p99 6.1. At the low end (0.2–0.252): CLS 0.01. At the high end (>p98): CLS 0.03. computed

The State of Web Vitals · Q1 2026 · 94,910 sites · all devices field datacorewebvitals.io/state-of-cwv
4

Why this matters for the Core Web Vitals, and where to start fixing it

Two sites can have the same CLS for opposite reasons. One has a single big jump. The other moves a little, everywhere, all the time. This ratio separates them: the largest shift divided by the total. Close to one means one event causes nearly all the damage. Find that element, reserve its space, and the score follows.

A low concentration is the harder case. No single shift looks bad, but they add up. That pattern points at scroll-triggered animations, CSS transitions on layout properties, or content that streams in piece by piece. There is no one bug to fix, so it needs a structural pass instead of a patch.

How does this affect the Core Web Vitals?

Shift concentration is part of the CLS itself, so this is arithmetic, not correlation. Where the shift concentration is low, 89% of sites pass the CLS. Where it is high, 72% do. The decline is gradual. There is no point where sites suddenly start failing.

Go fix it Scroll-triggered animations cause CLS → Layout shift caused by CSS transitions → Identify and fix CLS →
Related signals Largest single shift → Layout shift count → Shift direction → What shifted → Chrome field data from 94,910 sites, representing millions of real page loads · How we measured