The State of Web Vitals

HTTP protocol

The HTTP protocol of the HTML document response.

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 HTTP protocol

The HTTP protocol of the HTML document response.

3
Categories
185,262 sites
61.5%
Top share
h2
86ms
Top INP
Median for h2

23.6% of HTML documents arrive over HTTP/3.

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

HTTP protocol who uses what, and how fast each group loads

Median INP
0
100ms
200ms
300ms
400ms
500ms
h286ms62% of sites
http/1.186ms15% of sites
h387ms24% of sites
VariantShare of sitesMedian
h2 114,003 sites
62%
86ms
http/1.1 27,603 sites
15%
86ms
h3 43,656 sites
24%
87ms

Little daylight between the groups: every variant sits near 86ms median INP. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
3

Passing INP per HTTP protocol which group passes the INP most often

VariantSitesPassing INPINP
H2 61.5% 114,003 95% 86ms
H3 23.6% 43,656 95% 87ms
Http/1.1 14.9% 27,603 93% 86ms
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good INP (200ms at p75) · one value per site

No variant stands out: pass rates sit between 93% and 95%. computed

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

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

The protocol decides how expensive a connection is. HTTP/3 sets up in fewer round trips and a lost packet no longer stalls everything behind it, which TCP-based protocols suffer from. The document request is where this matters most: it is the first request of the visit and it carries the whole TTFB.

There is a catch on the very first visit. Browsers often discover HTTP/3 support through a header on a previous response (Alt-Svc), so the first document fetch can still pay the older protocol's price. DNS HTTPS records fix that discovery, and your CDN controls whether they exist.

How does this affect the Core Web Vitals?

HTTP protocol correlates with the LCP. With H3, 86% of sites pass the LCP. With H2, 81% do.

Go fix it TTFB: connection duration → Configure Cloudflare for passing the Core Web Vitals →
Related signals Uncompressed text responses → HTML size (kB) → Connection hints → ETag present → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured