The State of Web Vitals

HTML size (kB)

The transfer size of the HTML document.

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

At a glance the headline numbers for HTML size (kB)

The transfer size of the HTML document.

21 KB
on the typical site
half of sites sit at or below
41 KB
1 in 4 sites exceed this
the top quarter
269 KB
the heaviest 1%
the long tail
185,477
sites measured
phone field data

The typical HTML document weighs 21 KB.

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

Distribution & median INP site count and median INP at each level of HTML size (kB)

0ms 63ms 125ms 188ms 250ms
200ms
0 75024 150047
0–49 50–99 100+
Good (≤200ms) Needs improvement Poor (>500ms) Site count
The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
3

Passing INP by HTML size (kB) which level passes the INP most often

HTML size (kB)SitesPassing INPINP
0–49 150,047 92% 96ms
50–99 21,133 91% 112ms
100+ 14,297 90% 103ms
Good Needs Improvement Poor Faded rows: under 100 sites

HTML size (kB) 21 KB. p75 41 KB. p99 269 KB. At the low end (0–49 KB): INP 96ms. At the high end (100+ KB): INP 103ms. computed

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

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

HTML size is parse-and-discover time. The browser reads the document from the top, and everything it should find early (the stylesheets, the LCP image) sits deeper in a big document. Very large HTML usually means inlined payloads: base64 images, server-rendered JSON state, giant inline scripts.

The early bytes matter most. The first network round trip delivers only the start of the document, so what sits in the head decides what the browser can do while the rest streams in. Keep the head lean and put the critical references early.

Go fix it Preload the LCP image → Eliminate render-blocking resources → 103 Early Hints →
Related signals HTTP protocol mix → HTTP protocol → ETag present → Cache strategy mix → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured