ALTCHA is described as 'Privacy-first solution built to help developers and website owners stop bots, spam, and automated abuse — without making things harder for real users. It replaces traditional CAPTCHA systems with a smarter, quieter approach to verification and threat detection' and is a Anti-Spam tool in the security & privacy category. There are more than 10 alternatives to ALTCHA for a variety of platforms, including Web-based, SaaS, Self-Hosted, Wordpress and Docker apps. The best ALTCHA alternative is Cap Captcha, which is both free and Open Source. Other great apps like ALTCHA are Anubis, reCAPTCHA, Procaptcha and Private Captcha.
Lightweight, modern open-source CAPTCHA alternative designed using SHA-256 proof-of-work.
Cap Captcha is the most popular Self-Hosted alternative to ALTCHA.
Cap Captcha is the most popular Open Source & free alternative to ALTCHA.
Applies sha256 proof-of-work challenges to incoming HTTP requests, targeting AI crawlers, bots that ignore robots.txt, and automated scrapers, protecting server resources and preventing unwanted search engine indexing for privacy-focused sites.
reCAPTCHA is a free service that protects your site from spam and abuse, using risk analysis techniques to tell humans and bots apart.
reCAPTCHA is the most popular Web-based alternative to ALTCHA.
Prosopo Procaptcha redefines user verification with a unique approach that emphasizes privacy and security. It's a pioneering solution designed to offer an alternative to conventional CAPTCHA systems that often compromise user privacy.
Procaptcha is the most popular SaaS alternative to ALTCHA.
Private Captcha is an 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.
hCaptcha is designed to solve the most labor intensive problem in machine learning: labeling massive amounts of data in a timely, affordable, and reliable way.
Turnstile is Cloudflare's smart CAPTCHA alternative. It automatically chooses from a rotating suite of non-intrusive browser challenges based on telemetry and client behavior exhibited during a session.
mosparo is the modern solution for protecting your online forms from spam. The protection method is quite simple: mosparo blocks spam using rules matching the form’s data. The detection method is comparable to an e-mail spam filter.
TrustCaptcha is a privacy-first, invisible CAPTCHA that protects your website from bots and spam—without disrupting your users.
Anti-Spam Features. CleanTalk protects your website from spam bots and spam in Comments, Orders, Widgets, Registrations, Bookings, And any custom web form, Contact Emails, Subscriptions, Checks the existing comments and users for spam.
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