WCAG accessibility levels and success criteria explained

Discussions regarding the Web Content Accessibility Guidelines (WCAG) highlight the distinctions between conformance levels A, AA, and AAA. The classification of Success Criteria (SC) is based on factors such as whether a requirement is essential for overall access, the difficulty of implementation, and the availability of workarounds. For example, keyboard access is classified as Level A because it is fundamental, whereas sign language requirements are Level AAA due to the significant effort required for implementation.

There is also technical distinction between WCAG 1.4.4 Resize Text and 1.4.10 Reflow. Success Criterion 1.4.4 (Level AA) focuses on text resizing up to 200% without loss of content or functionality, allowing for methods like browser zooming or viewport resizing, even if it results in horizontal scrolling. In contrast, 1.4.10 Reflow is designed to support low-vision users by ensuring content can be presented at a width of 320px without requiring horizontal scrolling, focusing on layout behavior rather than text size itself.