Zero Captcha

The simplest way to add a zero friction captcha in your Rails forms.

A zero captcha works off the idea that most simple bots do not run a full JavaScript interpreter when crawling web forms, so they are unable to fill a required field whereas the required field is actually hidden and autopopulated by JavaScript in a real browser with a real human. This means having a layer of spam protection while maintaining zero friction.

This should not be used solely by itself, but can be useful as an extra layer of defense alongside honeypot captchas and/or more traditional captchas.

Requires Rails 5+

In your Gemfile, simply add

gem 'zero-captcha'

Simply specify that the form has a honeypot in the HTML options hash:

<% form_for Comment.new, html: { zero_captcha: true } do |form| -%>
  ...
<% end -%>

Simply specify that the form has a honeypot in the options hash:

<% form_tag comments_path, zero_captcha: true do -%>
  ...
<% end -%>

Simply specify that the form has a honeypot in the options hash:

<%= form_tag comments_path, zero_captcha: true -%>
  ...
</form>

By default, zero-captcha works by checking against a verify value if provided. If not provided, zero captcha will not activate.

However, if you wish to force the presence of a zero-captcha value, you may use this in your controller:

prepend_before_filter :require_zero_captcha, only: [:create]

See LICENSE for details.