The State of Web Vitals

Iframes per page

How many iframes the page embeds.

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

At a glance the headline numbers for Iframes per page

How many iframes the page embeds.

0
on the typical site
half of sites sit at or below
2
1 in 4 sites exceed this
the top quarter
8
the heaviest 1%
the long tail
94,748
sites measured
phone field data

The typical page embeds 0 iframes.

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

Distribution & median LCP site count and median LCP at each level of iframes per page

0ms 750ms 1500ms 2250ms 3000ms
2.5s
0 26889 53777
0 1 2 3 4 5 6 7–8 >p98
Good (≤2.5s) Needs improvement Poor (>4s) Site count
The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
3

Passing LCP by iframes per page which level passes the LCP most often

Iframes per pageSitesPassing LCPLCP
0 53,777 84% 1.5s
1 16,457 82% 1.6s
2 11,100 79% 1.7s
3 5,386 79% 1.7s
4 3,538 78% 1.7s
5 1,758 78% 1.7s
6 1,026 79% 1.7s
7–8 934 76% 1.8s
>p98 772 73% 1.9s
Good Needs Improvement Poor Faded rows: under 100 sites

Iframes per page 0. p75 2. p99 8. At the low end (0): LCP 1.5s. At the high end (>p98): LCP 1.9s. computed

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

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

Each iframe is a separate document with its own resources, scripts and lifecycle, and its work still competes for the same device. The count is a decent proxy for embed weight: chat widgets, videos, ad slots, forms.

Every embed should justify itself. The heavy default (always-on iframe) has a light replacement for almost every case: a facade for video and chat, a static image for maps, a reserved slot for ads.

How does this affect the Core Web Vitals?

Iframes correlate with the CLS. With few iframes, 91% of sites pass the CLS. With many, 76% do. The decline is gradual. There is no point where sites suddenly start failing.

Go fix it Chat widgets with perfect Core Web Vitals → Perfect YouTube Core Web Vitals → Speed up a Calendly integration →
Related signals Responsive image markup → Image fetchpriority → Script coverage (used vs unused) → Bytes by resource type → Chrome field data from 94,910 sites, representing millions of real page loads · How we measured