Is a cookie banner a problem for accessibility?

Cookie banners can genuinely fail to meet the standard

Yes, a cookie banner is regularly an accessibility issue, and that surprises most entrepreneurs because they see the banner as something legal and not as part of the website. Yet a cookie banner is simply a piece of interface: it contains buttons, sometimes a toggle per cookie category, and the banner appears on top of the rest of the page. All these elements fall under the same requirements as the rest of the site — WCAG 2.1 level AA, which in practice amounts to EN 301 549.

The problems that occur in practice are concrete. A banner that can only be closed with the mouse excludes someone who navigates with the keyboard — comparable to what can go wrong with keyboard operation throughout the entire checkout. A banner that does not retain focus lets a screen reader or keyboard user navigate "through" the banner to underlying content that is not yet visible or operable, comparable to the problems that arise with focus order and visible focus. It also happens that the "accept" and "reject" buttons are visible but have no clear name for a screen reader, or that the contrast of the text on the banner is too low to read.

What that amounts to: WCAG criteria like any other part

WCAG 2.1 does not set separate rules for cookie banners — the standard describes requirements for all operable elements on a page, whether it is a button in the navigation or a button in a banner that appears on screen after two seconds. Research by ACM into the accessibility of web shops shows that this is not a theoretical point: banners and overlays on web shops are among the parts where problems are found, alongside more familiar issues such as colour contrast or unclear forms. For those curious about how such a toggle should sound to a screen reader, comparable background can be found at form fields and labels that are not read out correctly.