Imunify360

Cloudflare Turnstile is a smart CAPTCHA alternative designed to provide a more user-friendly and privacy-focused approach to bot detection. It uses non-interactive challenges and machine learning to validate users without requiring them to solve puzzles or identify objects.

Akamai Web Application Protector is a cloud-based security solution designed for companies seeking an automated approach to web application firewall (WAF) and distributed denial-of-service (DDoS) protection. It provides real-time threat intelligence and adaptive security measures to defend against evolving web application attacks.

Friendly Captcha is an innovative proof-of-work based CAPTCHA alternative where the user's device performs computational work to prove humanity. This approach provides effective bot protection while offering a seamless, accessible user experience without traditional CAPTCHA challenges.

DDoS-Guard is a Russian Internet infrastructure company that provides a range of services including DDoS protection, content delivery network (CDN) services, and web hosting. Their solutions help websites and online services maintain availability and performance in the face of distributed denial-of-service attacks.

Slider Captcha is a free service that helps protect websites from spam and abuse.