Rack middleware Captcha verification using Recaptcha API.

ActsAsTextcaptcha provides spam protection for Rails models with text-based logic question captchas. Questions are fetched from Rob Tuley's textcaptcha.com They can be solved easily by humans but are tough for robots to crack.

Despamilator is a plugin based spam detector designed for use on your web forms borne out of two annoyances: Spam being submitted in my web forms and CAPTCHAS being intrusive. Despamilator will apply some commonly used heuristics from the world of anti-spam to help you decide whether your users a...

Rails extension for Cloudflare's Turnstile CAPTCHA alternative. This gem should work with Rails 6.x and 7.x, and with Faraday 1.x and 2.x.

AntiCaptcha api ruby wrapper

RubyGem package for visualCaptcha's backend service

Arithmetic Captcha

SimpleCaptcha is available to be used with Rails 3 or above and also it provides the backward compatibility with previous versions of Rails.

Drop in feedback engine with customizable fields, and captcha available

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A honeypot style captcha extension for ActiveRecord. Simple one-line inclusion in the model combined with a simple form field should trap the bad guys in the molasses.

This version include two important page 'Contact' and 'Register' with the 'Math-Captcha' method submit for prevent hacker attack.

Russian Post tracking toolset, consisting tracking form bot (since Russian Post is too retarded for normal API) and captcha solver/recognizer.

Merb plugin that provides resource access rate limits and captcha'ing

LoyalSimpleCaptcha is available to be used with Rails 3 or above and also it provides the backward compatibility with previous versions of Rails.

Helps humankind with simpler captchas

This is a gem wrapper for tiny captcha in C with no dependencies.

Define questions and answers in a YAML file and validate your models with a single line of code. No more captchas or other stupid tricks.

This plugin adds helpers for the YinXiangMa CAPTCHA API

A captcha that uses images instead of garbled text