CAPTCHA & Bot Protection
49,994 of the 1,000,000 top sites in our Tranco top-1M census run Cloudflare Turnstile (5%). Cloudflare's non-interactive CAPTCHA replacement, bundled free with its CDN/WAF. Detection is homepage-level HTML/header fingerprinting, so a site can run Cloudflare Turnstile on other pages without it showing here.
Other captcha & bot protection
| # | Domain | Global traffic rank | Contacts |
|---|---|---|---|
| 1 | x.com | #54 (Tranco) | Find emails |
| 2 | discord.com | #163 (Tranco) | Find emails |
| 3 | flickr.com | #172 (Tranco) | Find emails |
| 4 | soundcloud.com |
| Site | Tranco rank | Also detected | Contacts |
|---|---|---|---|
| cambridge.org | #654 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| anydesk.com | #681 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| cursor.sh | #703 | Amazon Route 53, Cloudflare Bot Management, Cloudflare edge/CDN + 7 more | Find emails |
| #176 (Tranco) |
| Find emails |
| 5 | nist.gov | #231 (Tranco) | Find emails |
| perplexity.ai | #707 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| mediafire.com | #710 | Amplitude, Bootstrap, Cloudflare + 15 more | Find emails |
| stripchat.com | #723 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 7 more | Find emails |
| iso.org | #738 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 2 more | Find emails |
| openstreetmap.org | #770 | Apache, Cloudflare, Fastly + 4 more | Find emails |
| 33across.com | #798 | Cloudflare Bot Management, Cloudflare edge/CDN, Sectigo | Find emails |
| academia.edu | #821 | Amazon Route 53, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| pexels.com | #825 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 4 more | Find emails |
| discogs.com | #844 | Amazon Route 53, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| chess.com | #861 | Adyen, Cloudflare, Cloudflare Bot Management + 4 more | Find emails |
| themeforest.net | #886 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 5 more | Find emails |
| tawk.to | #890 | Cloudflare, Cloudflare Web Analytics, Cloudflare edge/CDN + 11 more | Find emails |
| flashtalking.com | #894 | AWS Lambda, Adobe Fonts (Typekit), Ahrefs Analytics + 11 more | Find emails |
| claude.ai | #901 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| umich.edu | #946 | Cloudflare Bot Management, Cloudflare edge/CDN, Google Trust Services | Find emails |
| nexusmods.com | #979 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| columbia.edu | #982 | Cloudflare Bot Management, Cloudflare edge/CDN, Google Trust Services | Find emails |
| kickstarter.com | #989 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| ox.ac.uk | #1,031 | Cloudflare Bot Management, Cloudflare edge/CDN, Google Trust Services | Find emails |
| sofascore.com | #1,033 | Cloudflare, DoubleClick (Google Ads), Google Publisher Tag + 3 more | Find emails |
| oecd.org | #1,043 | Azure DNS, Cloudflare Bot Management, Cloudflare edge/CDN + 2 more | Find emails |
| letterboxd.com | #1,060 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
Showing the first 10,000matches — add a filter to narrow.
From the Crawlora Website Tech Stack Dataset, a homepage-level fingerprint of a 1,000,000-domain Tranco top-1M census (run top1m-2026-08-24-full), snapshot August 24, 2026. Directional, not exhaustive — fully custom or bundled stacks under-detect. Methodology →