Lightweight, modern open-source CAPTCHA alternative designed using SHA-256 proof-of-work.
Portugal
EU
IronWall Alternatives
IronWall is described as 'Proof-of-Work (PoW) rate-limiting protocol designed to protect high-value API endpoints (AI generation, Auth, SMS triggers) from automated abuse' and is an app in the security & privacy category. There are more than 25 alternatives to IronWall for a variety of platforms, including Web-based, Self-Hosted, SaaS, JavaScript and PHP apps. The best IronWall alternative is Cap Captcha, which is both free and Open Source. Other great apps like IronWall are reCAPTCHA, Private Captcha, Cloudflare Turnstile and hCaptcha.
Alternatives list
28 reCAPTCHA alternativesreCAPTCHA is a free service that protects your site from spam and abuse, using risk analysis techniques to tell humans and bots apart.
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.
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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)
Cost / License
- Freemium
- Proprietary
Application type
Platforms
- Online
- Software as a Service (SaaS)
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.
TrustCaptcha is a privacy-first, invisible CAPTCHA that protects your website from bots and spam—without disrupting your users.
Cost / License
- Freemium
- Proprietary
Application type
Platforms
- Online
- Spring
- Kotlin
- Rust
- Ruby
- Python
- .NET Framework
- Craft CMS
- React
- Groovy
- JavaScript
- Angular
- Software as a Service (SaaS)
- Scala
- PHP
- Go (Programming Language)
- Typescript
- Java
- Wordpress
- Node.JS
- Vue.js
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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.
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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...
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Cost / License
- Freemium
- Proprietary
Platforms
- Online
- Self-Hosted
- Software as a Service (SaaS)
United States
Estonia
Germany
Czechia
Switzerland
India
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