reCAPTCHA

reCAPTCHA is a free CAPTCHA service that helps to digitize books, newspapers and old time radio shows. About 200 million CAPTCHAs are solved by humans around the...

Free Web

127 Like

hCaptcha

hCaptcha allows websites to make money serving this demand while blocking bots and other forms of abuse.

Freemium Web

3 Like

Mollom

Mollom is a freemium web service to get rid of spam, unwanted content and fake users on your Drupal, Wordpress and Joomla site or blog.

• Discontinued
  "The Mollom content moderation service is no longer available … as of 2 April 2018."

Freemium Web

2 Like

visualCaptcha

A configurable captcha solution, focusing on accessibility & simplicity whilst maintaining security.

• Discontinued
  As from Dec 26, 2016: Please note visualCaptcha is no longer actively developed. It still works and should continue to, but it won't be improved by the initial team anymore. ... Source: https://github.com/emotionLoop/visualCaptcha/blob/master/README.md

Free Open Source Self-Hosted

3 Like

UniqPin

UniqPin is a free for non-commercial use service which destiny improve ability of interfaces detect a human or a computer operate with it. Surpassing a CAPTCHA...

Free Personal Self-Hosted JavaScript PHP

3 Like

GeeTest CAPTCHA

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...

Commercial Software as a Service (SaaS)

1 Like

MTcaptcha

Enterprice captcha service with no captcha capabilities. GDPR and Accessibility (WCAG 2.1) Compliant.

Commercial $ $ $ Software as a Service (SaaS)

2 Like

FeedCaptcha

FeedCaptcha is a new captcha system, easy to integrate and with meaning for your product. You create a set of questions that users answers in order to pass the captcha...

Freemium $ $ $ Web Software as a Service (SaaS)

1 Like

Confident Captcha

Confident Technologies provides free CAPTCHA security software called Confident CAPTCHA, a picture CAPTCHA that stops spam and bots. Download our free CAPTCHA security...

Freemium Web

2 Like

Negative Captcha

A plugin to make the process of creating a negative captcha in Rails much less painful.

Free Open Source Self-Hosted

0 Like