The State of Web Vitals

Scripts per page

How many scripts the page runs and their over-the-wire weight.

Field data PhoneDesktopAll Scope All sites Q2 2026 edition · All devices field outcomes
Metric LCP INP CLS
1

At a glance the headline numbers for Scripts per page

How many scripts the page runs and their over-the-wire weight.

26
script count
on the typical page
552 KB
script weight
on the typical page
1,006 KB
1 in 4 pages exceed this
script weight
180,684
sites measured
all-device field data

The typical page runs 26 scripts weighing 552 KB.

The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
2

Distribution & median CLS site count and median CLS at each level of scripts per page — n

0.00 0.04 0.08 0.11 0.15
0.1
0 17736 35472
0 1–2 3 4 5–7 8–11 12–18 19–30 31–48 49–78 79–126 >p98
Good (≤0.1) Needs improvement Poor (>0.25) Site count
The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
3

Passing CLS by scripts per page — n which level passes the CLS most often

Scripts per page — nSitesPassing CLSCLS
0 3,961 89% 0.00
1–2 4,652 86% 0.00
3 2,889 86% 0.00
4 3,345 88% 0.00
5–7 10,175 89% 0.00
8–11 14,846 89% 0.00
12–18 26,268 90% 0.00
19–30 35,472 89% 0.00
31–48 33,797 87% 0.00
49–78 26,704 87% 0.01
79–126 15,132 86% 0.01
>p98 3,443 78% 0.03
Good Needs Improvement Poor Faded rows: under 100 sites

Scripts per page — n 26. p75 49. p99 156. At the low end (0): CLS 0.00. At the high end (>p98): CLS 0.03. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
4

Distribution & median CLS site count and median CLS at each level of scripts per page — size

0.00 0.04 0.08 0.11 0.15
0.1
0 35564 71127
0 0.1–0.28 0.28–0.784 0.784–2.2 2.2–6.15 6.15–17.2 17.2–48.2 48.2–135 135–378 378–1060 1060–2968 >p98
Good (≤0.1) Needs improvement Poor (>0.25) Site count
The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
5

Passing CLS by scripts per page — size which level passes the CLS most often

Scripts per page — sizeSitesPassing CLSCLS
0 763 83% 0.00
0.1–0.28 15 100% 0.00
0.28–0.784 147 89% 0.00
0.784–2.2 326 93% 0.00
2.2–6.15 571 93% 0.00
6.15–17.2 1,505 95% 0.00
17.2–48.2 3,496 95% 0.00
48.2–135 15,226 94% 0.00
135–378 42,449 91% 0.00
378–1060 71,127 88% 0.00
1060–2968 36,960 82% 0.01
>p98 3,507 67% 0.04
Good Needs Improvement Poor Faded rows: under 100 sites

Scripts per page — size 552 KB. p75 1,006 KB. p99 3.7 MB. Spearman with CLS r = +0.31. At the low end (0 KB): CLS 0.00. At the high end (>p98): CLS 0.04. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
6

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

Script weight is the most expensive weight. A kilobyte of JavaScript costs more than a kilobyte of image, because after the download it is parsed, compiled and executed on the main thread. That is the same thread that must answer every click and keystroke, which is why script totals track INP.

The count matters next to the bytes: every script is a potential long task and another spot for the main thread to stall. Most pages would lose nothing by deferring most of their scripts. The ones that truly must run early are rare.

How do scripts affect the Core Web Vitals?

Scripts per page correlates with the INP. Script count separates passing sites from failing sites more than script weight does. Where the script count is low, 80% of sites pass the INP. Where it is high, 91% do. The rise is gradual.

Go fix it 14 methods to defer JavaScript → Reduce unused JavaScript → JavaScript priority levels →
Related signals DOM size → Page weight & requests → Image source mix → Stylesheet loading mix → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured