Technical Questions About WCAG and Accessibility
What are accessibility overlays and why don't they work?
Answer
Accessibility overlays are JavaScript widgets intended to retroactively adapt a website. Leading accessibility experts and disability associations explicitly warn against these tools: they do not solve the structural problems in the source code and can even worsen the experience for people with disabilities. The BFSG requires structural accessibility in the source code (Source: W3C WAI, Overlay Fact Sheet).