Bot Detection Benchmarked Against AI Agents: 9%–99%

Researchers tested detection systems including Proof of Human, reCAPTCHA v3, hCaptcha and Cloudflare Turnstile against conventional automation, stealth browsers and AI browsing agents, finding detection rates ranging from 9% to 99% versus 33%–87% a year earlier. Performance varied widely, and some systems failed or crashed before sessions completed.

• Anthropic: AI agents struggle with CAPTCHAs2026-09-10