The State of Web Vitals

LCP responsive markup

Responsive markup on the LCP image: srcset, picture, or none.

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

At a glance the headline numbers for LCP responsive markup

Responsive markup on the LCP image: srcset, picture, or none.

3
Categories
90,431 sites
78.5%
Top share
no
1.6s
Top LCP
Median for no

78.5% of LCP images ship without responsive markup.

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

LCP responsive markup who uses what, and how fast each group loads

Median LCP
0
0.5s
1s
1.5s
2s
2.5s
3s
3.5s
4s
picture1.5s7% of sites
srcset1.5s14% of sites
no1.6s79% of sites
VariantShare of sitesMedian
picture 6,582 sites
7%
1.5s
srcset 12,828 sites
14%
1.5s
no 71,021 sites
79%
1.6s

Little daylight between the groups: every variant sits near 1.5s median LCP. computed

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
3

Passing LCP per LCP responsive markup which group passes the LCP most often

VariantSitesPassing LCPLCP
Picture 7.3% 6,582 88% 1.5s
Srcset 14.2% 12,828 84% 1.5s
No 78.5% 71,021 81% 1.6s
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good LCP (2.5s at p75) · one value per site

88% of Picture sites pass LCP. No trails 7 points behind. 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

A phone should not download the desktop hero. srcset and picture let the browser pick the file that fits the viewport, which directly cuts the LCP's load time on small screens. Without them, every device downloads the largest image someone uploaded.

The win is biggest exactly where LCP is hardest: small screens on slow connections. Most CMSs generate the size candidates automatically. The gaps are usually hand-written templates and page builders.

How does this affect the Core Web Vitals?

LCP responsive markup correlates with the LCP. With Picture, 88% of sites pass the LCP. With No, 81% do.

Go fix it Optimize images for Core Web Vitals → Optimize the LCP image → Fix slow hero images →
Related signals LCP priority hint → LCP discovery → LCP image size → LCP origin → Chrome field data from 94,910 sites, representing millions of real page loads · How we measured