Headings should be created in an hierarchical order

In the current implementation, it is possible to have skipped heading levels. For example on the Search pages you often have H1 followed directly by one or more H3.

As per WCAG 2.1 AA, the ruling is to ensure that correct HTML semantics are used. But in one of the WCAG technique (H42: Using h1-h6 to identify headings | WAI | W3C) suggested to implement the headings states that heading markup should indicate the appropriate heading level for the content.

Note that it is not required to implement the WCAG technique. You can achieve the same objective in various ways such as using ARIA instead of html mark up in this case. But when WCAG technique is implemented, it will make your site more accessible and at the same time, usable.

Below are some of the adverse impacts when using inconsistent headings:

• Headings provide context about the content that follows. Inconsistent headings can confuse users, making it hard to determine the relationship between sections and the importance of content.

• Screen reader users often rely on headings to navigate a page. Inconsistent or improperly structured headings can make it difficult for them to understand the layout and hierarchy, hindering efficient navigation.

• Users with cognitive disabilities may struggle with understanding the structure and flow of the content. Consistent headings help in reducing cognitive load by providing a clear, predictable structure.

Though it is not a direct WCAG failure, but it would be highly recommended that the headings are created in an hierarchical order.