Accessibility overlay

A software layer, typically implemented as a JavaScript widget or browser extension, that applies modifications to a website's presentation or behavior with the goal of improving accessibility. Overlays range from user-driven tools that empower individuals to fix specific barriers they encounter (such as the Accessmonkey framework, which allowed blind users to create and share page-specific accessibility scripts) to commercial products that claim to automate WCAG compliance through automated transformations. The accessibility community is broadly critical of commercial overlay products, as they typically cannot detect or fix underlying structural accessibility issues such as missing semantic markup, incorrect reading order, or absent keyboard support, and may introduce new barriers or interfere with assistive technology. User-driven overlay approaches, by contrast, are generally viewed more favorably as they put control in the hands of people with disabilities, though they face sustainability challenges when the underlying website changes.