hCaptcha is described as 'Is designed to solve the most labor intensive problem in machine learning: labeling massive amounts of data in a timely, affordable, and reliable way' and is a Anti-Spam tool in the security & privacy category. There are more than 25 alternatives to hCaptcha, not only websites but also apps for a variety of platforms, including Self-Hosted, SaaS, PHP and JavaScript apps. The best hCaptcha alternative is Cap Captcha, which is both free and Open Source. Other great sites and apps similar to hCaptcha are Anubis, reCAPTCHA, Procaptcha and Private Captcha.