The State of Web Vitals

Loading Strategies

Q1 2026 | 45,022 sites
All Desktop Phone
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Speculation Rules
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Preload adoption
44.0%
Uncompressed text

Resource hint adoption, speculation rules, compression algorithms, caching strategy, and script loading patterns.

HTTP protocol

Median LCP (sites using feature)
0
0.5s
1s
1.5s
2s
2.5s
3s
3.5s
4s
h21.5s56% of sites
h31.6s34% of sites
http/1.11.6s10% of sites
h2
56%
1.5s
h3
34%
1.6s
http/1.1
10%
1.6s

HTTP protocol. On the fleet: 55.5% h2, 34.2% h3, 10.3% http/1.1. 94.4% of sites use at least one h2.

Cache strategy

Median LCP (sites using feature)
0
0.5s
1s
1.5s
2s
2.5s
3s
3.5s
4s
unspecified1.5s35% of sites
long_ttl1.5s25% of sites
medium_ttl1.5s17% of sites
immutable1.5s11% of sites
short_ttl1.6s8% of sites
no_store1.6s3% of sites
no_cache1.6s2% of sites
unspecified
35%
1.5s
long_ttl
25%
1.5s
medium_ttl
17%
1.5s
immutable
11%
1.5s
short_ttl
8%
1.6s
no_store
3%
1.6s
no_cache
2%
1.6s

Cache strategy. On the fleet: 35.2% unspecified, 24.9% long_ttl, 16.7% medium_ttl. 97.6% of sites use at least one unspecified.

Lowest-share bucket: LCP 1.2s. Highest-share bucket: LCP 1.5s. r = +0.48.

ETag adoption

ETag adoption
87.7%

87.7% of sites send ETag headers (39,489 of 45,022). With send: LCP 1.5s, 82.9% pass. Without: LCP 1.4s, 84.3% pass.

Last-Modified adoption

Last-Modified adoption
95.5%

95.5% of sites send Last-Modified headers (43,001 of 45,022). With send: LCP 1.5s, 82.8% pass. Without: LCP 1.3s, 87.5% pass.

Correlates with +223ms LCP and −4.7 pp pass rate.