Cloudflare Challenge
A verification step Cloudflare shows to visitors it suspects are bots before allowing access to a site, ranging from an invisible JS check to an interactive puzzle.
Full Definition
A Cloudflare challenge is any interstitial Cloudflare inserts between the visitor and the site when its bot score algorithm is uncertain about the request. The lightest form is an invisible JavaScript challenge that runs silently in the browser and checks for correct execution environment, timing, and fingerprint. A managed challenge presents a brief "Checking your browser…" page before auto-resolving. A CAPTCHA challenge shows a Turnstile or reCAPTCHA puzzle. Each level requires progressively more human-like capability to pass. Scraping infrastructure that uses rotating residential proxies, realistic fingerprints, and proper TLS signatures can often pass the invisible challenge level without any CAPTCHA.
