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 |
|---|---|---|---|
| redbubble.com | #2,935 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 9 more | Find emails |
| toasttab.com | #2,939 | Amazon Route 53, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| newsbreak.com | #2,953 | AWS Lambda, Amazon (ACM), Amazon CloudFront + 23 more | Find emails |
| #176 (Tranco) |
| Find emails |
| 5 | nist.gov | #231 (Tranco) | Find emails |
| calameo.com | #2,985 | Amazon Route 53, Bootstrap, Cloudflare Bot Management + 13 more | Find emails |
| ubereats.com | #3,004 | Adobe Audience Manager, Amazon Advertising, Arkose Labs + 36 more | Find emails |
| ucsb.edu | #3,009 | AddToAny, ConsentMo, Drupal + 9 more | Find emails |
| laracasts.com | #3,016 | Cloudflare, Cloudflare edge/CDN, Fastmail + 1 more | Find emails |
| namecheap.com | #3,017 | Cloudflare Bot Management, Cloudflare edge/CDN, Namecheap + 1 more | Find emails |
| unimelb.edu.au | #3,108 | Cloudflare Bot Management, Cloudflare edge/CDN, Let's Encrypt | Find emails |
| ex.co | #3,117 | Amazon Route 53, Cloudflare Bot Management, Cloudflare edge/CDN + 20 more | Find emails |
| ed.ac.uk | #3,124 | Drupal, Fastly, Google Tag Manager + 6 more | Find emails |
| guard.io | #3,146 | AWS Lambda, Adobe Fonts (Typekit), AppsFlyer + 18 more | Find emails |
| flic.kr | #3,154 | Adobe Fonts, Adobe Fonts (Typekit), Amazon (ACM) + 15 more | Find emails |
| ning.com | #3,199 | Amazon Route 53, Font Awesome, Google Analytics + 13 more | Find emails |
| justia.com | #3,227 | Amazon Route 53, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| isc.org | #3,241 | Apache, Azure API Management, Bootstrap + 19 more | Find emails |
| ko-fi.com | #3,247 | AWS Lambda, Bootstrap, Cloudflare + 18 more | Find emails |
| usp.br | #3,264 | Apache, Font Awesome, Google Analytics + 6 more | Find emails |
| hopkinsmedicine.org | #3,290 | Cloudflare Bot Management, Cloudflare edge/CDN, Let's Encrypt | Find emails |
| com.com | #3,296 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| trouble-free.net | #3,309 | Cloudflare, Cloudflare Bot Management, Cloudflare edge/CDN + 1 more | Find emails |
| postman.com | #3,357 | Amazon CloudFront, Amazon Route 53, Amazon S3 + 29 more | Find emails |
| feedly.com | #3,375 | Calendly, Cloudflare, Cloudflare edge/CDN + 6 more | Find emails |
| bitly.com | #3,417 | Amazon (ACM), Amazon Route 53, Cloudflare Bot Management + 13 more | Find emails |
| pushwoosh.com | #3,442 | Amazon CloudFront, Astro, Cloudflare Bot Management + 7 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 →