ReCaptcha implements view helpers to generate ReCaptcha code, with the noscript counterpart, required methods that interface with the HTTP API for captcha verification, a DSL to generate a before_filter and the code to implement AJAX captcha validation.

A simple image captcha gem

generate captcha by dalli,use the memcache

RedisCaptcha provides simple captcha that can be read by human.

DeathByCaptcha allows you to solve captchas with manual labor

Rack middleware Captcha verification using Recaptcha API.

BrainBuster - a logic captcha for Rails

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 are human or machine.

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AntiCaptcha api ruby wrapper

Drop in feedback engine with customizable fields, and captcha available

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

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.

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

Arithmetic Captcha

RubyGem package for visualCaptcha's backend service

Arithmetic Captcha

jQuery slide captcha system with jQuery & jQuery UI for Rails 3