Home › Knowledge base › Topic

Overlay tools and accessibility

Overlay modules promise accessibility via a code snippet. In practice they do not solve the underlying problems and sometimes create new ones.

What they do

They place a control bar over the page (contrast toggle, text enlargement) and try to fill in missing alt texts or ARIA roles automatically.

Why that is not enough

Automatically guessed alt texts and roles are often wrong. Screen-reader users bring their own tools and do not need the bar. The structural errors (keyboard traps, headings, form labels) remain. Hundreds of affected people and experts have spoken out publicly against overlays; there have been lawsuits despite overlay use.

The better way

Create accessibility in the source code — semantic HTML, real labels, sufficient contrast, keyboard operation. A scan shows where to start.

How a11yglass helps

The free scan checks the delivered HTML and CSS for automatically recognisable WCAG breaches, and names per finding the success criterion and a concrete step. It finds roughly 20–35% of issues and does not replace a full assessment.

Read on

• The EAA for websites
• The four WCAG principles
• Testing accessibility

General information to the best of our knowledge, not legal advice. For an individual case, contact a law firm specialising in IT law.