A Captcha allows you to protect your website from spam. Generally CAPTCHA are created by a distorted picture punctuation without (obviously) adding an alt text.
This is a problem for users of screen readers. See also Guideline 1.1 of WGAC 2.0:
Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.
To provide a readable CAPTCHA for visitors with screenreading software, it’s possible to use (simple) mathematical questions. This could be in numbers, words or a combination. For example:
3 x 2 =?
three + eight =?
six – 4 =?
Accessible captcha plugin
Plugin captcha for WordPress, developed by BestWebSoft, intends to prove that the visitor is a human being and not a spam robot, by asking the visitor to answer a math question. The plugin can be used for login, registration, reseting password, comments forms.
- Display: It is possible to use letters and numbers in the captcha or just one of these two things – either letters or numbers.
- Actions: The basic mathematical operations are used – add, subtract, multiply.
- Label: There is a possibility to add a label when displaying captcha on the form.