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ID #329

What is CAPTCHA? How can I use it?

Applies to: Grid System

What is CAPTCHA?
In a CAPTCHA test (an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart," also sometimes spelled in lowercase), an image of letters is dynamically generated. The letters, because they're part of an image and not text (e.g. text that you could cut and paste), are difficult for a spambot or other computer program to read. Yet, a person has little trouble reading the letters in a CAPTCHA image.

Using a CAPTCHA test on a website is a great way to ensure that a person, and not a spambot, is filling out a web form. Also, a CAPTCHA can make it difficult for a person to continuously resubmit form information and overwhelm the form's purpose.

If you need a CAPTCHA to protect your for from bots, Modwest strongly recommends you used reCAPTCHA on your forms. ReCAPTCHA is easy to implemet, difficult for bots to defeat, and accessible to the blind. Learn more about it here.

If you prefer not to use reCAPTCHA, many creative CAPTCHAs are listed at captcha.net.  We advise you use one of the sanctioned ones to protect your forms, as homemade CAPTCHAs frequently suffer from security and accessiblilty concerns. 


Last update: 2011-12-22 17:01
Author: FAQ Admin
Revision: 1.4

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