Websites using Cloudflare challenge platform
Cloudflare's challenge platform runs bot detection and JavaScript challenges for Bot Management and the WAF. About 153,994 websites in the PageSourceSearch index contain the code that reveals it; the 50 highest-ranked are listed below.
How is Cloudflare challenge platform detected?
Cloudflare injects a script that loads from /cdn-cgi/challenge-platform/ into pages it protects. The discovery keyword is the exact bytes PageSourceSearch looks for in every stored page and script:
/cdn-cgi/challenge-platform/ Search the index for it
A literal is matched byte for byte, case-sensitively. Combine it with another keyword, a domain, a kind or a date filter on the search page to narrow the list. About Cloudflare challenge platform
Top 50 websites using Cloudflare challenge platform
Ranked by the domain's position in the crawl's ranked list (Common Crawl harmonic centrality), highest first. view source opens the stored page or script with the match highlighted. Computed 2026-09-29 18:40:15 UTC.
How it appears in the source
From microsoft.com (html):
a3fe90f2d9ad340b',t:'MTc5MDIxOTExMw=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElementsByTagName('head')[0].appendChild(a);";b.getEl
Questions about finding Cloudflare challenge platform
- How does PageSourceSearch know a website uses Cloudflare challenge platform?
- By the source itself: Cloudflare injects a script that loads from /cdn-cgi/challenge-platform/ into pages it protects. PageSourceSearch stores the raw HTML and first-party JavaScript of each crawled site and matches the keyword byte for byte, so every listed site's stored source contains it.
- Is this a complete list of websites using Cloudflare challenge platform?
- No. The page lists the 50 highest-ranked sites in the index whose source holds the keyword, out of about 153,994 websites that do; the count is the index's estimate at the time the list was computed. Run the keyword as a search to page through all of them, or add a kind or date filter.
- How do I find websites that use Cloudflare challenge platform together with another technology?
- Search for both keywords at once: several terms separated by spaces must all be found on the same site, or with the Same page toggle in the same page. For example /cdn-cgi/challenge-platform/ with wp-content/plugins/ lists the WordPress sites that use Cloudflare challenge platform.