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
IronWall AlternativesAnti-Spam Tools and other similar apps like IronWall
Apps similar to IronWall include Cap Captcha, which is free and open source. Other options are reCAPTCHA, Private Captcha, Cloudflare Turnstile and ALTCHA. There's no shortage of Anti-Spam Tools like IronWall, with more than 25 alternatives for the web, self-hosting and Linux.
Alternatives list
- 36 Cap Captcha alternatives
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
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.
Cost / License
- Free Personal
- Proprietary
Application type
Platforms
- Online
- Self-Hosted
- Docker
Estonia- EU
+1
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
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
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
- Germany
- EU
+4
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
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
Cost / License
- Freemium
- Proprietary
Platforms
- Online
- Self-Hosted
- Software as a Service (SaaS)
Synthient identifies the infrastructure behind an IP address so fraud, abuse, and security teams can make better decisions. The platform detects residential and datacenter proxies, commercial VPNs, relays, bot infrastructure, and other anonymizers.
Cost / License
- Paid
- Proprietary
Application type
Platforms
- Online
- United States
