The State of Web Vitals

Loading Strategies

Q1 2026 | Desktop | 17,554 sites
All Desktop Phone
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Speculation Rules
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Preload adoption
43.4%
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
h21.3s56% of sites
h31.4s34% of sites
http/1.11.4s10% of sites
h2
56%
1.3s
h3
34%
1.4s
http/1.1
10%
1.4s

HTTP protocol. On the fleet: 56.4% h2, 33.5% h3, 10.1% http/1.1. 94.1% 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
unspecified1.3s36% of sites
long_ttl1.4s25% of sites
medium_ttl1.4s17% of sites
immutable1.4s10% of sites
short_ttl1.4s8% of sites
no_store1.4s3% of sites
no_cache1.4s2% of sites
unspecified
36%
1.3s
long_ttl
25%
1.4s
medium_ttl
17%
1.4s
immutable
10%
1.4s
short_ttl
8%
1.4s
no_store
3%
1.4s
no_cache
2%
1.4s

Cache strategy. On the fleet: 35.6% unspecified, 24.8% long_ttl, 17.1% medium_ttl. 97.5% of sites use at least one unspecified.

Lowest-share bucket: LCP 995ms. Highest-share bucket: LCP 1.3s. r = +0.48.

ETag adoption

ETag adoption
88.1%

88.1% of sites send ETag headers (15,468 of 17,554). With send: LCP 1.3s, 87.6% pass. Without: LCP 1.2s, 87.9% pass.

Correlates with +170ms LCP and −0.3 pp pass rate.

Last-Modified adoption

Last-Modified adoption
95.3%

95.3% of sites send Last-Modified headers (16,737 of 17,554). With send: LCP 1.3s, 87.6% pass. Without: LCP 1.2s, 87.1% pass.

Correlates with +162ms LCP and +0.5 pp pass rate.