CAPTCHAs
Where possible, avoid the use of CAPTCHAs.
However, where anti-spam measures must be adopted in forms, use World Wide Web Consortium (W3C) techniques to allow CAPTCHAs to be accessible. This typically requires providing the CAPTCHA test in more than one format (for example, visual and auditory versions) and providing a text alternative that describe these formats.
Learn more
The World Wide Web Consortium (W3C) provides information on the ‘inaccessibility of CAPTCHA: alternatives to visual turing tests on the web’