You may recall a blog post we wrote a few months ago about audio CAPTCHAs and the problems they present.  We came to the conclusion that the audio CAPTCHAs option is usually too distorted for most people to interpret.  Since then we have discovered a few alternatives that may be more accessible.

Images

This type of CAPTCHA will typically ask users to select a specific picture from a series of images.  For example, there may be three pictures of animals and the test will ask you to pick the picture with ducks in it, which a spam bot could not do.  Confident CAPTCHA is one service that does this.  While this form of CAPTCHAs might make it easier for someone who has a print disability, these photographs don’t always have alt tags for screen readers.

Multiple Choice

CAPTCHAs sometimes take the form of an incomplete sentence in which users are to select an appropriate answer to fill in the blank (sound like English class?)  For example, you may be given the sentence “The _____ barks at cats that walk by.”  Choices might include “truck”, “yellow”, and “dog”.  This is purely text based, so a screen reader would be able to identify it like any other sentence on the screen.

Logic Puzzles

CAPTCHAs that use logic puzzles are similar to the multiple choice version in that they require you to answer a question correctly.  An example would be “The last letter in ‘happiness’ is?”  Another example would be a math puzzle, like “Six plus 10 is?”  Text CAPTCHA has over 150 million questions that are geared towards 7-year-old level.

There are several variations on the CAPTCHA tests mentioned above.  Although none of them are completely without issue, they certainly appear to be more accessible than the distorted images or audio clips.  We will continue to keep our ears to the ground and follow up on future developments.