CAPTCHA

A CAPTCHA is a challenge-response test most often placed within web forms to determine whether the user is human. The purpose of CAPTCHA is to block form submissions by spambots, which are automated scripts that post spam content everywhere they can.

The CAPTCHA module provides this feature to virtually any user facing web form on a Drupal site. The administration settings for CAPTCHA are available at admin/user/captcha.

Additional CAPTCHA Modules

• reCAPTCHA
• CAPTCHA Pack
• Egglue Semantic CAPTCHA
• Captcha Riddler

Other Information

• Join the CAPTCHA Drupal Group
• Talk live on #Drupal-Captcha
• Watch the Drupal CAPTCHA Tutorial video

Alternatives

One of the disadvantages of using CAPTCHAs is that you can drive away legitimate users. You could also consider spam filtering or hybrid solutions like:

• The AntiSpam module, is the successor of the Akismet module, and it provides spam protection to your drupal site using external antispam service like Akismet, TypePad and Defensio.
• The Mollom module, similar to AntiSpam module, it only presents a CAPTCHA if the user input (e.g. a comment) looks like spam. It is restricted to the Mollom antispam service
• The spam module provides spam filtering and related tools