Revised "Inaccessibility of CAPTCHA" Draft for Review

Author(s) and publish date

Skip to 8 comments

Today the Accessible Platform Architectures (APA) Working Group, with extensive assistance from its Research Questions Task Force (RQTF), published a draft update to the W3C Note "Inaccessibility of CAPTCHA". This widely accessed publication from 2005 has been extensively revised and updated to bring it up to date with changes in technology since it was last published. Much has changed in technology since then, but CAPTCHAs remain a barrier for some people to access websites.

We are attempting to survey the landscape of existing approaches and their accessibility challenges and solutions comprehensively in this update. We have also conducted an extensive review of relevant research literature in creating this revised draft, which is incorporated into the document with citations. We were able to include additional information about federated identity systems, dual factor authentication, and biometrics, which are now more broadly used. New types of CAPTCHAs, such as 3d and video game CAPTCHAs, are also emerging which present new opportunities and challenges for accessibility.

Web Content Accessibility Guidelines 2.0 and 2.1 refer to the requirement for accessible CAPTCHA in Success Criterion 1.1.1 Non-Text Content. This document is an important complement to that requirement which provides more detail on how to meet these requirements, and relevant considerations in accessible authentication of Web users.

We have endeavored to comprehensively cover the current landscape in technologies that attempt to distinguish human web site users from robots. To be sure the updated document is as complete as possible, we need public input on this version. The following questions will help guide your review:

  • Does this document fully capture current problems with CAPTCHA and related systems?
  • Are there other potential solutions that should be added?
  • Are there concerns for certain categories of persons with disabilities that remain unaddressed or insufficiently addressed in this document?
  • Are you aware of relevant research in this area we missed?

To comment, file an issue in the W3C apa GitHub repository. If this is not feasible, send email to (comment archive). Comments are requested by 31 July 2018. In-progress updates to the document may be viewed in the publicly visible editors' draft.

This publication returns the document to Working Draft status. After incorporation of feedback, and probably at least one more public review draft, the Working Group plans to advance this document back to Note status. The 2005 CAPTCHA Note is still available.

Related RSS feed

Comments (8)

Comments for this post are closed.