The State of Web Vitals

HTTP protocol mix

The HTTP protocol carrying each request: h1, h2, h3.

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

At a glance the headline numbers for HTTP protocol mix

The HTTP protocol carrying each request: h1, h2, h3.

3
Categories
In the distribution
55.2%
Fleet share
Top: h2
94.4%
Sites with any
Of h2

34.2% of requests travel over HTTP/3. 10.6% still use HTTP/1.1.

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

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

Median LCP (sites using feature)
0
0.5s
1s
1.5s
2s
2.5s
3s
3.5s
4s
H21.6s55% of sites
H31.6s34% of sites
Http/1.11.6s11% of sites
VariantShare of sitesMedian
H2
55%
1.6s
H3
34%
1.6s
Http/1.1
11%
1.6s

HTTP protocol mix. On the fleet: 55.2% h2, 34.2% h3, 10.6% http/1.1. 94.4% of sites use at least one h2.

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

Passing LCP per bucket every category and count level at once - color is the pass rate

1
2
3
4
5
6
7
8
9
10
11
H2 55.2%
86
85
84
86
87
87
87
83
75
66
63
H3 34.2%
82
80
79
77
77
79
84
83
79
89
88
Http/1.1 10.6%
79
79
83
85
82
83
81
84
81
79
66
← few of this category on the pagemany →
60%95%+ of sites passing LCP Faded cells: under 100 sites

Each row is a category, each column its own count bucket (few on the left, many on the right); the cell is the share of those sites passing LCP.

H2 swings the hardest: 86% of sites pass LCP with few, 63% with many. computed

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

Few vs many - does quantity cost LCP? the pass rate with few vs many of each category

60%70%80%90%100% few → many
H2 55.2% 86% → 63%
Http/1.1 10.6% 79% → 66%
H3 34.2% 82% → 88%
% of sites passing LCP · hollow ring = pages with few, solid dot = pages with many

Per category: the pass rate among pages with FEW of it (hollow ring) against pages with MANY (solid dot), worst trend first. Thin buckets are excluded from the endpoints.

More H2 costs the most: the LCP pass rate falls from 86% with few to 63% with many. computed

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
5

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

HTTP/1.1 gives you a handful of parallel requests per domain and queues the rest. HTTP/2 multiplexes any number of requests over one connection. HTTP/3 keeps that and removes the last stall: on HTTP/2 a single lost packet blocks every stream on the connection, on HTTP/3 only the stream that lost it.

A modern protocol also amplifies consolidation. The fewer domains you use, the more requests share one warm HTTP/3 connection. Requests still travelling over HTTP/1.1 are queueing for no reason.

How does this affect the Core Web Vitals?

The choice barely moves the LCP: 82% pass at best, 81% at worst. This signal does not separate passing sites from failing ones.

Go fix it Third-party domains → Configure Cloudflare for passing the Core Web Vitals →
Related signals Connection hints → Main CDN → HTTP protocol → HTML compression → Chrome field data from 94,910 sites, representing millions of real page loads · How we measured