Lightweight, modern open-source CAPTCHA alternative designed using SHA-256 proof-of-work and JS instrumentation
Cost / License
- Free
- Open Source
Application type
Platforms
- Self-Hosted
- Docker
Portugal
EU
Invisible Anti-Spam & CAPTCHA AlternativesAnti-Spam Tools and other similar apps like Invisible Anti-Spam & CAPTCHA
Apps similar to Invisible Anti-Spam & CAPTCHA include Cap Captcha, which is free and open source. Other options are reCAPTCHA, Private Captcha, ALTCHA and Procaptcha. You're spoiled for choice with Anti-Spam Tools like Invisible Anti-Spam & CAPTCHA: we list more than 25 alternatives for the web and self-hosting.
Alternatives list
35 reCAPTCHA alternativesreCAPTCHA is a free service that protects your site from spam and abuse, using risk analysis techniques to tell humans and bots apart.
Cost / License
- Freemium
- Proprietary
Application type
Platforms
- Online
United States
25 Private Captcha alternativesPrivate 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.
Cost / License
- Free Personal
- Proprietary
Application type
Platforms
- Online
- Self-Hosted
- Docker
Estonia- EU
+1
ALTCHA is a 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.
Czechia- EU
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.
Cost / License
- Freemium
- Open Source (Apache-2.0)
Application typeApplication types
Platforms
- Online
- Software as a Service (SaaS)
- Wordpress
United Kingdom
+3
Say Goodbye to comment spam on your WordPress blog or website. Antispam Bee blocks spam comments and trackbacks effectively, without captchas and without sending personal information to third party services. It is free of charge, ad-free and 100% GDPR compliant.
Cost / License
- Free
- Open Source
Application type
Platforms
- Self-Hosted
- Wordpress
Germany- EU
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.
Cost / License
- Free
- Proprietary
Platforms
- Online
- JavaScript
- Software as a Service (SaaS)
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.
Switzerland
+9
18 Akismet alternativesAkismet checks your comments and contact form submissions against our global database of spam to prevent your site from publishing malicious content.
Cost / License
- Free Personal
- Proprietary
Application type
Platforms
- Self-Hosted
- Wordpress
Friendly Captcha is an invisible CAPTCHA and bot protection solution that helps block bots and spam with privacy-first proof-of-work-without image or audio puzzles, cookies, or user tracking. GDPR- and CCPA-compliant and TÜV-certified as conformant with WCAG 2.
- Germany
- EU
India
