The State of Web Vitals

Speculation posture

The strongest speculation rule the document declares: none, prefetch, prerender-until-script, prerender.

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

At a glance the headline numbers for Speculation posture

The strongest speculation rule the document declares: none, prefetch, prerender-until-script, prerender.

4
Categories
94,890 sites
65.0%
Top share
none
101ms
Top INP
Median for none

65.0% of sites declare no speculation rules at all.

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

Speculation posture who uses what, and how fast each group loads

Median INP
0
100ms
200ms
300ms
400ms
500ms
prerender_until_script76ms0% of sites
prefetch96ms34% of sites
none101ms65% of sites
prerender104ms1% of sites
VariantShare of sitesMedian
prerender_until_script 269 sites
0%
76ms
prefetch 32,465 sites
34%
96ms
none 61,678 sites
65%
101ms
prerender 478 sites
1%
104ms

Little daylight between the groups: every variant sits near 76ms median INP. computed

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

Passing INP per speculation posture which group passes the INP most often

VariantSitesPassing INPINP
Prefetch 34.2% 32,465 97% 96ms
Prerender until script 0.3% 269 96% 76ms
Prerender 0.5% 478 91% 104ms
None 65% 61,678 90% 101ms
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good INP (200ms at p75) · one value per site

97% of Prefetch sites pass INP. None trails 7 points behind. computed

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

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

Speculation rules let the browser start the next navigation before the click. Prefetch downloads the next document ahead of time. Prerender goes further and builds the whole next page in a hidden renderer, so navigating to it is a swap instead of a load. Prerender-until-script is the cautious middle: build the page, hold the scripts.

Done right, the next page's LCP is near-instant because it painted before the visitor arrived. The cost is speculative work: prerendering pages nobody visits burns server and client resources. That trade is what eagerness controls.

How does this affect the Core Web Vitals?

Speculation posture correlates with the INP. With Prefetch, 97% of sites pass the INP. With None, 90% do. The causal link is weak: the choice mostly marks what kind of site made it.

The split is bigger on LCP. With None, 86% of sites pass it. With Prefetch, 73% do.

Go fix it Speculation rules → The prerender-until-script speculation rule → View transitions and web performance →
Related signals Speculation eagerness → Chrome field data from 94,910 sites, representing millions of real page loads · How we measured