Full definition
Cloudflare sits between many websites and the public internet, providing CDN, DDoS protection, and a heavy-hitting anti-bot product. When a site is "behind Cloudflare", every request you make goes through Cloudflare's edge first — and Cloudflare can challenge it with a CAPTCHA, JavaScript puzzle, or outright block based on IP reputation, TLS fingerprint, header order, and behavioral signals.
Bypassing Cloudflare reliably requires: (1) high-trust residential or mobile IPs — datacenter IPs hit Cloudflare's wall instantly, (2) realistic TLS fingerprint (JA3) matching a real browser, (3) proper header order matching what real browsers send, and (4) proper handling of the Cloudflare clearance cookie once you pass a challenge.
Most major proxy providers now ship "Cloudflare bypass" or "Web Unlocker" products that handle (1)–(4) automatically — Bright Data Web Unlocker, Oxylabs Web Unblocker, Smartproxy Site Unblocker. Expect to pay $1–$3 per 1,000 successful requests.