Castle Device Intelligence vs IPQS Proxy Detection API: Side-by-Side Comparison (2026)

Short answer

SMB and mid-market teams protecting high-value accounts from credential stuffing and account takeover will see immediate ROI from Castle Device Intelligence, since its 99.5% accuracy device fingerprinting catches stolen credentials being used from unfamiliar devices in real time. The 150ms API response time means you're not adding latency to login flows, and the cookie-independent identification works even when attackers clear browser data. Skip this if you need behavioral analytics or post-breach forensics; Castle is built for preventing account compromise at the perimeter, not investigating it after the fact. Startups and SMBs blocking fraudulent access at scale will see immediate ROI from IPQS Proxy Detection API; its 25+ data point IP reputation scoring catches residential proxies and datacenter botnets that generic blocklists miss. The API handles bulk CSV uploads for batch enforcement and integrates directly into authentication flows, covering the PR.AA and DE.CM functions that actually prevent account takeover. Skip this if you need a unified threat platform; IPQS does one thing, detection, and doesn't handle response or recovery.