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CDN & hosting

Cloudflare in Homepage Source

Cloudflare is a global CDN, security and performance provider fronting a large share of the web.

The source-code fingerprint

Cloudflare injects /cdn-cgi/ asset paths into pages it serves, email-address obfuscation, Rocket Loader, challenge scripts and the analytics beacon all live under it, so the path marks sites genuinely behind Cloudflare.

Likely false positives: A proxied site with no Cloudflare-injected feature can omit the path, and a page can reference another site's /cdn-cgi/ URL, rare in practice.

Stored source examples for Cloudflare

These examples matched /cdn-cgi/ in stored homepage source when the query was sampled on 2026-10-14. The sites may have changed since the source was captured. A match establishes a source reference; it does not confirm an active installation or code execution.

• medium.com ...};var a=document.createElement('script');a.nonce='';a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• stackoverflow.com ...};var a=document.createElement('script');a.nonce='';a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• discord.com ...;a.nonce='MjE3LDE4MywyMjQsMTY1LDYyLDc1LDEwOSwyMTM=';a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• payhip.com ... <img src="https://payhip.com/cdn-cgi/image/format=auto,width=600/https://pe56d.s3.amazonaws.com/...
• datatracker.ietf.org ...MxMjQ5MA=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• lnk.bio ...ort for the free version, but drop us an email to <a href="/cdn-cgi/l/email-protection#53202623233c2127133f3d387d313a3c" class=...
• www.notion.so ...ion.so/zh-tw"/><link rel="preload" as="image" imageSrcSet="/cdn-cgi/image/format=webp,width=1080/front-static/pages/product/sup...
• www.acm.org ...="WeChat" />\r\n\t\t\t\t\t</a>\r\n\t\t\t\t</li>\r\n\t\t\t<li>\r\n\t\t\t\t\t<a href="/cdn-cgi/l/email-protection#3253515f5a575e427253515f1c5d4055" target...
• www.nist.gov ... </address>\n <p>\n <a href="/cdn-cgi/l/email-protection#0e6a6123796b6c636f7d7a6b7c4e60677d7a2069...
• qz.com ...as="image" fetchPriority="high" imageSrcSet="https://qz.com/cdn-cgi/image/width=128,quality=85,format=auto/https://assets.qz.co...
• www.prnewswire.com ....0px;">\r\n<li style="text-align: left;">Submit via <a href="/cdn-cgi/l/email-protection#6515170c1304061c25060c160c0a0b4b060a08">...
• csrc.nist.gov ...xt-right">\r\n Send inquiries to <a href="/cdn-cgi/l/email-protection#61021213024c080f1014081318210f0812154f06...
• www.ietf.org ...Q1Mzg5Nw=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• speakerdeck.com ...UxODI0Nw=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• www.anthropic.com ...y(override.toUpperCase());\n return;\n }\n\n fetch('/cdn-cgi/trace')\n .then(function (res) {\n return res.tex...
• www.epi.org ...QzMjkzMg=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• developers.cloudflare.com ...flex items-center gap-2" data-astro-cid-sbh7lytb><img src="/cdn-cgi/image/onerror=redirect,width=26,height=12,format=svg/_astro...
• www.zendesk.com ...l="preload" as="image" href="https://web-assets.zendesk.com/cdn-cgi/image/q=65,f=auto,width=1600,fit=scale-down/zendesk/pages/h...
• buffer.com ...nk rel="preload" as="image" imageSrcSet="https://buffer.com/cdn-cgi/image/width=640,quality=75,format=auto/img/homepage/social-...
• nvd.nist.gov ...ExMjg0Mg=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• www.smithsonianmag.com ...QxMDkzNA=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• notes.io ... <br>\n <p><b>Email: <a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="2048...
• haveibeenpwned.com ...once='Sbd13PwCr1KwoTexr067s0zquXLaqrJeBRBk4UPmCwQ=';a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• donorbox.org ...Y3MTYxOQ=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• vlang.io ...Are you using V to build your product or library? <a href="/cdn-cgi/l/email-protection#b4d5d8d1ccd5dad0d1c6929782808fc2d8d5dad3...
• acortar.link ...A2OTYyOA=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• www.uci.org ...\n Tel. +41 24 468 58 11\r\n </a>\r\n <a href="/cdn-cgi/l/email-protection#16757978627775625663757f38757e"><span cl...
• benn.substack.com ...c5NzE2Nw=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElement...
• pydata.org ...div class="et_pb_header_content_wrapper"><p>Email <a href="/cdn-cgi/l/email-protection#3f5e5b5256517f4f465b5e4b5e11504d58"><spa...
• gifct.org ...ct Us</span></h3></div><div class="textwidget"><p><a href="/cdn-cgi/l/email-protection#f09f85848295919398b09799969384de9f8297">...

Showing 30 checked source examples. The headline is estimated matches. Open the full ranked list, inspect the matched source, and export the domain list →

Related technologies

How this works

The headline distinguishes candidate upper bounds (index prefilter), estimated matches (a projection from checked samples) and verified matches (an exact count established by the engine). The index contains 131,219,565 homepage documents, one homepage per hostname, including subdomains. The source index was promoted 2026-09-22 and follows a quarterly rebuild schedule. The sample date is when this query was checked against the stored index, not a new crawl of each example site.

Comparing adoption across tools? The Web Technology Adoption Report ranks the most common tags in the index side by side.