The State of Web Vitals

Main CDN

Which CDN, if any, serves the HTML document itself.

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

At a glance the headline numbers for Main CDN

Which CDN, if any, serves the HTML document itself.

7
Categories
185,262 sites
77.0%
Top share
origin
0.00
Top CLS
Median for origin

77.0% of HTML documents are served without a CDN.

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

Main CDN who uses what, and how stable each group is

Median CLS
0
0.05
0.10
0.15
0.20
0.25
origin0.0077% of sites
cloudflare0.0013% of sites
fastly0.004% of sites
akamai0.003% of sites
vercel0.001% of sites
netlify0.010% of sites
cloudfront0.023% of sites
VariantShare of sitesMedian
origin 142,621 sites
77%
0.00
cloudflare 23,785 sites
13%
0.00
fastly 6,437 sites
4%
0.00
akamai 4,955 sites
3%
0.00
vercel 980 sites
1%
0.00
netlify 343 sites
0%
0.01
cloudfront 6,141 sites
3%
0.02

Little daylight between the groups: every variant sits near 0.00 median CLS. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
3

Passing CLS per main CDN which group passes the CLS most often

VariantSitesPassing CLSCLS
Fastly 3.5% 6,437 88% 0.00
Origin 77% 142,621 88% 0.00
Cloudflare 12.8% 23,785 88% 0.00
Akamai 2.7% 4,955 86% 0.00
Vercel 0.5% 980 84% 0.00
Cloudfront 3.3% 6,141 78% 0.02
Netlify 0.2% 343 69% 0.01
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good CLS (0.1 at p75) · one value per site

88% of Fastly sites pass CLS. Netlify trails 19 points behind, leaving 31% of its sites failing. computed

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

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

Everything starts after the HTML arrives. The document's TTFB sits under every other phase: the browser cannot discover, download or render anything before it has the markup. Serving the document through a CDN terminates TLS close to the visitor, and when the HTML is edge-cached it removes the origin round trip completely.

HTML is the hardest thing to put on a CDN because it is the dynamic part. Full-page edge caching is the big win when the content allows it. Even without it, edge termination and a warm route to the origin cut the TTFB.

How does this affect the Core Web Vitals?

Main CDN correlates with the LCP. With Cloudflare, 86% of sites pass the LCP. With Netlify, 78% do.

The split is bigger on INP. With Akamai, 97% of sites pass it. With Netlify, 75% do.

Go fix it Configure Cloudflare for passing the Core Web Vitals → Time to First Byte → Free website cache warmer →
Related signals ETag present → Requests via CDN → HTTP protocol mix → HTTP protocol → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured