The Web Content Accessibility Guidelines (WCAG) contains basic guidance for creating a more accessible internet for people with disabilities. However, it’s not overly prescriptive — WCAG doesn’t tell you how to build each component of your website, nor does it require ugly, bland design.
Today, we’ll explore WCAG’s requirements for headings and subheadings, which most websites use to structure their content (and which usually improve experiences for folks with disabilities).
The Web Accessibility Initiative (WAI), which authors WCAG, describes headings as text that “communicates the organization of the content on the page.”
Note that this definition is not restricted to HTML headings. That’s intentional: Some digital formats may not use HTML, and WCAG is meant to apply to all types of digital products — not just websites. For example, web-delivered documents (such as PDFs) may not use HTML, but they can still contain headings.
For the purposes of conformance (and compliance with laws like the Americans with Disabilities Act), digital headings need to meet a few basic standards:
“Programmatically determinable" means that computer software can understand the structure of the page through its markup. In other words, subheadings must use HTML, ARIA, PDF tags, or another type of markup to tell software: “Hey, this section right here is a subheading.”
That's important because semantic markup gives more control to assistive technology users. People might want to jump from one subheading to the next without reading all of the rest of the content, or they might want to change the appearance of subheadings. If a subheading is visual-only, they won’t have that ability.
For a deeper explanation of how semantic markup impacts users, read: What "Programmatically Determined" Means for Accessibility.
You might have noticed that while WCAG provides some rules for using subheadings, it doesn’t require that websites use headings to organize content — at least, not at Level AA (learn about the different levels of WCAG conformance).
WCAG does explicitly require headings for Level AAA conformance under Success Criterion 2.4.10, “Section Headings.” The full text of that criterion reads:
Section headings are used to organize the content.
Even in this context, WCAG doesn’t specifically require HTML markup. As the authors note, “headings" includes titles and “other ways to add headings to different types of content.”
Remember, Level AAA criteria are often strict, but they’re worth your attention. This is a great example of a Level AAA requirement that most websites follow without even realizing it — though you’ll need to check a few things to make sure that you’re conforming with other relevant WCAG standards.
Related: Accessibility Tips: Don’t Use Subheadings Because of How They Look
To recap: WCAG doesn’t require headings or subheadings at Level AA, but if you do use subheadings, you need to use them correctly.
And unless you have a very, very simple website, you probably need subheadings to keep your content organized and readable. Unless you’ve got a complex website that needs to use ARIA for headings for some reason (and you probably don’t), you should identify your headings with HTML markup.
With that in mind, here’s a quick checklist that you can use to check your subheadings for accessibility:
To ensure your website meets WCAG standards, regular audits are essential. An automated tool like the Bureau of Internet Accessibility's Free WCAG Level AA Compliance Summary can identify common structural issues (including poor use of semantic HTML).
For more guidance, download the Bureau of Internet Accessibility’s Ultimate Guide to Web Accessibility.