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
reCAPTCHA AlternativesAnti-Spam Tools and other similar apps like reCAPTCHA
Sites and apps similar to reCAPTCHA include Cap Captcha, which is free and open source. Other options are Anubis, Cloudflare Turnstile, ALTCHA and Procaptcha. Anti-Spam Tools like reCAPTCHA are a crowded field, with more than 25 alternatives for self-hosting.
Alternatives list
58 Anubis alternativesApplies 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.
Cost / License
- Free Personal
- Open Source (MIT)
Application typeApplication types
Platforms
- Self-Hosted
- Go (Programming Language)
- Docker
Canada
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)
26 ALTCHA alternativesALTCHA 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
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
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
GeeTest protects your websites, mobile apps and APIs from bad bot attacks with zero user friction. Its self-learning defense model based on Graph Convolutional Networks and massive volumes of biometric data collected in the past 7 years allows GeeTest to identify and mitigate...
Cost / License
- Paid
- Proprietary
Application type
Platforms
- Software as a Service (SaaS)
China
+3
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
The Arkose Labs platform undermines the economic drivers behind fraud until perpetrators are compelled to abandon attacks. Real-time risk classification of traffic with interactive enforcement challenges, the solution defeats automated attacks...
Cost / License
- Paid
- Proprietary
Platforms
- Software as a Service (SaaS)
United States
India
