Skip to content
This repository


Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP

Rack Middleware for CAPTCHA verification via Recaptcha API

branch: master


Build Status

Drop this Rack middleware in your web application to enable CAPTCHA verification via Recaptcha API.

How to Use


First, install the library with: [sudo] gem install rack-recaptcha

You have to require 'rack-recaptcha' in your gemfile.

## Gemfile
gem 'rack-recaptcha', :require => 'rack/recaptcha'
Available options for `Rack::Recaptcha` middleware are:

* :public_key -- your ReCaptcha API public key *(required)*
* :private_key -- your ReCaptcha API private key *(required)*
* :proxy_host -- the HTTP Proxy hostname *(optional)*
* :proxy_port -- the HTTP Proxy port *(optional)*
* :proxy_user -- the HTTP Proxy user *(optional, omit unless the proxy requires it)*
* :proxy_password -- the HTTP Proxy password *(optional, omit unless the proxy requires it)*

Now configure your app to use the middleware. This might be different across each web framework.


## app.rb
use Rack::Recaptcha, :public_key => 'KEY', :private_key => 'SECRET'
helpers Rack::Recaptcha::Helpers


## app/app.rb
use Rack::Recaptcha, :public_key => 'KEY', :private_key => 'SECRET'
helpers Rack::Recaptcha::Helpers


## application.rb:
module YourRailsAppName
  class Application < Rails::Application
    config.gem 'rack-recaptcha', :lib => 'rack/recaptcha'
    config.middleware.use Rack::Recaptcha, :public_key => 'KEY', :private_key => 'SECRET'

## application_helper.rb or whatever helper you want it in.
module ApplicationHelper
  include Rack::Recaptcha::Helpers

## application_controller.rb or whatever controller you want it in.
class ApplicationController < ActionController::Base
  include Rack::Recaptcha::Helpers


The Rack::Recaptcha::Helpers module (for Sinatra, Rails, Padrino) adds these methods to your app:

Return a javascript recaptcha form

  recaptcha_tag :challenge

Return a non-javascript recaptcha form

  recaptcha_tag :noscript

Return a ajax recaptcha form

  recaptcha_tag :ajax

For ajax recaptcha's, you can pass additional options like:

  recaptcha_tag :ajax, :display => { :theme => 'red'}

For non-ajax recaptcha's, you can pass additional options like:

  # Overrides the key set in Middleware
  recaptcha_tag :challenge, :public_key => KEY

  # Adjust Height and/or Width
  recaptcha_tag :noscript, :height => 300, :width => 500

  # Adjust the rows and/or columns
  recaptcha_tag :challenge, :row => 3, :cols => 5

  # Set the language
  recaptcha_tag :noscript, :language => :en

To test whether or not the verification passed, you can use:


The recaptcha_valid? helper can also be overloaded during tests. You can set its response to either true or false by doing the following:

 # Have recaptcha_valid? return true

 # Or have it return false
 Rack::Recaptcha.test_mode! :return => false

For additional options and resources checkout the customization page


In Padrino, here's how you would use the helpers.

## new.haml
- form_tag '/login', :class => 'some_form', :method => 'post' do
  = text_field_tag :email
  = password_field_tag :password
  = recaptcha_tag(:challenge)
  = submit_tag "Submit"

## sessions.rb
post :create, :map => '/login' do
  if recaptcha_valid?

In rails, you'll need to use also use the raw method:

## new.html.haml
- form_tag '/login' do
  = raw recaptcha_tag(:challenge)
  = submit_tag "Submit"


Daniel Mendler - minad

  • support for multiple paths and helpers clean up

Eric Anderson - eric1234

  • Make verify independently usable.

Chad Johnston - iamthechad

  • Adding Error Message handling in recaptcha widget

Eric Hu - eric-hu

  • Patching error message issue when no request is present

Tobias Begalke - elcamino

  • Added HTTP Proxy support

Julik Tarkhanov - julik

  • Adding rack-recaptcha to travis-ci

Rob Worley - robworley

  • Adding language setting for recaptcha form

sam71 - sam71

  • Fix recaptcha hanging when used in proxy environment.

Note on Patches/Pull Requests

  • Fork the project.
  • Make your feature addition or bug fix.
  • Add tests for it. This is important so I don't break it in a future version unintentionally.
  • Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
  • Send me a pull request. Bonus points for topic branches.


Copyright (c) 2010, 2011, 2012 Arthur Chiu. See LICENSE for details.

Something went wrong with that request. Please try again.