Accessibility gotchas with CAPTCHAs

Abstract

Does your website use a CAPTCHA, one of those blurred images of text or muffled audio files that a user must transcribe to prove they’re human before they are able to send an email/comment or complete a transaction? Have you ever been so frustrated by one of these when shopping or trying to send information to a friend that you simply abandoned your task? CAPTCHAs can create accessibility barriers that violate web accessibility guidelines designed to make the web an inclusive place. Although CAPTCHAs have become more accessible over the years, many solutions still present one or more obstacles to users with visual, physical, cognitive or auditory disabilities. If your client requires the use of a CAPTCHA, what are the best alternatives for enterpriselevel websites? This paper begins with some background on CAPTCHAs and accessibility before comparing the different types of CAPTCHAs and what makes them inaccessible to some users. Finally, it explores the practical approach taken by CGI to solve this problem for one client who required the use of a CAPTCHA but also needed an accessible solution that supported multiple languages and did not rely on a third-party service.