The State of Web Vitals

Cacheable responses

The share of responses that carry cacheable headers.

Field data PhoneDesktopAll Scope All sites Q2 2026 edition · Phone field outcomes
Metric LCP INP CLS
1

At a glance the headline numbers for Cacheable responses

The share of responses that carry cacheable headers.

64.8%
on the typical site
half of sites sit at or below
84.2%
1 in 4 sites exceed this
the top quarter
98.1%
the heaviest 1%
the long tail
185,271
sites measured
phone field data

64.8% of responses on the typical site are cacheable.

The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
2

Distribution & median CLS site count and median CLS at each level of cacheable responses

0.00 0.04 0.08 0.11 0.15
0.1
0 17781 35561
0 0–10 10–20 20–30 30–40 40–50 50–60 60–70 70–80 80–90 90–100 100
Good (≤0.1) Needs improvement Poor (>0.25) Site count
The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
3

Passing CLS by cacheable responses which level passes the CLS most often

Cacheable responsesSitesPassing CLSCLS
0 21,737 92% 0.00
0–10 20,273 89% 0.00
10–20 15,946 88% 0.00
20–30 9,394 88% 0.00
30–40 6,325 87% 0.00
40–50 5,480 84% 0.00
50–60 7,987 86% 0.00
60–70 13,272 86% 0.00
70–80 23,090 87% 0.00
80–90 35,561 91% 0.00
90–100 25,559 91% 0.00
100 647 96% 0.00
Good Needs Improvement Poor Faded rows: under 100 sites

Cacheable responses 64.8%. p75 84.2%. p99 98.1%. At the low end (0): CLS 0.00. At the high end (100): CLS 0.00. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
4

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

This is the share of responses a browser is allowed to keep. Everything outside that share gets re-downloaded on the next visit. Repeat visitors are in your field data too, and for them cacheability is the difference between reading from disk and crossing the network.

Uncacheable static assets are almost always an accident: a missing header on a font, a no-cache default on an image bucket. If a file has a hash in its name, there is no reason it should ever be fetched twice.

How does caching affect the Core Web Vitals?

Cacheable share correlates with the LCP. Where the cacheable share is low, 84% of sites pass the LCP. Where it is high, 95% do. The rise is gradual.

Go fix it TTFB: cache duration → Configure Cloudflare for passing the Core Web Vitals →
Related signals HTML compression → Cache strategy mix → HTTP protocol mix → HTTP protocol → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured