Private Captcha is described as 'Independent, privacy-first, self-hostable Proof-of-Work CAPTCHA service made in EU. Instead of asking users to solve complex puzzles or track their behavior, Private Captcha solves an invisible cryptographic task in the background' and is a Anti-Spam tool in the security & privacy category. There are more than 25 alternatives to Private Captcha for a variety of platforms, including SaaS, Web-based, Self-Hosted, Wordpress and Python apps. The best Private Captcha alternative is Cap Captcha, which is both free and Open Source. Other great apps like Private Captcha are Anubis, reCAPTCHA, Procaptcha and ALTCHA.
NoBot CAPTCHA API is a developer-friendly alternative to Google reCAPTCHA that helps prevent automated bot traffic without compromising user privacy.
