CAPTCHA Codes are not Accessible
CAPTCHA tests are showing up like crazy these days to validate that users are humans, and not computers. They are used in blog comments, and are getting popular for online registration sites.
I think that most people implementing captcha's these days are overlooking the fact that they are not accessible, and they would fail Section 508 accessibility compliance for a web application.
Nearly 10% of the population is color blind, and even more can't see very well. Some CAPTCHA codes are hard for me to read and I am not color blind, and have 20/20 vision. Just take a look at the CAPTCHA code on slashdot to see what I mean.
By the way CAPTCHA is an acronym for "completely automated public turing test to tell computers and humans apart."
Like this? Follow me ↯Tweet Follow @pfreitag
CAPTCHA Codes are not Accessible was first published on June 09, 2005.
If you like reading about captcha, accessibility, or section508 then you might also like:
- Target Sued over Accessibility
- Blogger adds Audio CAPTCHA
- Accessibility and Usability in Forms Outline
From a section 508 perspective, One method is to provide a phone number to call for an activation code. The alt/title field would contain the challenge code which the user punches into the phone and the person or automated system provides the response to be entered into the text field. If you are using an 800 number, you have the added advantage of being able to guarantee caller id, since the person paying for the phone call (you being the 800 number owner) has a right to know who's calling you.
I wonder if you couldn't just get around this by having Flash dyamic querying the server and display a string to display.
This wouldn't address accessibility, but might allow you to display an easier to read string.
I tend to stay away from them if I can.
GigoIt's HumanAuth is based off the ideas presented by KittenAuth.com. HumanAuth supports ADA and Section 508 requirements, increased security and includes watermarked images with random positioning. HumanAuth ensures that an actual human is using your site without forcing them to read distorted CAPTCHA text.