Website accessibility means that a person with a visual, hearing, motor or cognitive impairment can also use the site. The international reference framework is the WCAG criteria, which are divided into three levels of strictness, with the middle level being the commonly required one. The practical requirements are specific: sufficient colour contrast of text, alternative descriptions for images, full keyboard operability of the entire site, a visible focus indicator on the focused element, understandable form field labels, captions for videos, and a correct heading structure. Most of these measures also improve usability for everyone and help with machine processing of content. Accessibility is cheapest to address at the design stage – retrofitting a finished website tends to be significantly more expensive than accounting for the rules from the start. Even a non-technical person can perform a basic check: navigating the site with the keyboard alone and trying to operate it without a mouse reveals most major shortcomings.
See also: European Accessibility Act, Heading hierarchy, Image descriptions for AI.
