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 INP (sites using feature)
0
100ms
200ms
300ms
400ms
500ms
H299ms55% of sites
H3101ms34% of sites
Http/1.1103ms11% of sites
VariantShare of sitesMedian
H2
55%
99ms
H3
34%
101ms
Http/1.1
11%
103ms

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 INP 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%
90
93
93
91
91
92
92
94
93
92
87
H3 34.2%
93
94
94
94
92
91
92
91
91
94
89
Http/1.1 10.6%
93
92
93
94
91
88
87
87
88
92
91
← few of this category on the pagemany →
60%95%+ of sites passing INP 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 INP.

No category moves the INP pass rate much, however many a site ships. 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 INP? the pass rate with few vs many of each category

60%70%80%90%100% few → many
H3 34.2% 93%89%
H2 55.2% 90%87%
Http/1.1 10.6% 93%91%
% of sites passing INP · 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 H3 costs the most: the INP pass rate falls from 93% with few to 89% 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.

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