Missing Heading Structure

A missing or broken heading structure occurs when a page lacks a clear hierarchy of h1 through h6 elements, skips heading levels (e.g., jumping from h1 to h3), uses multiple h1 elements without semantic justification, or has no h1 at all. WCAG Success Criterion 1.3.1 (Level A) requires that information, structure, and relationships conveyed through visual presentation are also available programmatically -- and headings are the primary mechanism for conveying document structure.

Screen reader users rely heavily on heading navigation. Most screen readers offer a shortcut (H key in NVDA and JAWS) to jump between headings, effectively using them as a table of contents. When headings are skipped or missing, this navigation method breaks down, and users lose their sense of where they are within the page hierarchy.

The problem often arises because developers choose heading levels for their visual size rather than their semantic meaning. A developer may use an h3 simply because the h3 CSS style matches the desired font size, skipping h2 entirely. Others use divs or spans styled to look like headings but lacking any semantic heading role, making them invisible to assistive technologies.

For screen reader users, headings are the most important navigation tool on a page. According to the WebAIM screen reader user survey, nearly 70% of users navigate pages by headings as their first strategy. When the heading hierarchy is broken or absent, these users must listen through the entire page content linearly to find what they need -- a process that can take minutes on a long page.

Skipped heading levels create confusion about the content hierarchy. If a page jumps from h1 to h3, a screen reader user may wonder if they missed an h2 section or if the content structure is simply unreliable. Missing h1 elements leave users unsure of the page's main topic.

Beyond accessibility, heading structure is a significant SEO factor. Search engines use headings to understand page content and hierarchy. A page with a clear h1 and well-organized subheadings ranks better than one with a chaotic or missing heading structure.

Scrutia parses the heading structure of every page and builds a hierarchical outline. It flags pages with no h1 element, multiple h1 elements, skipped heading levels, and elements styled as headings but lacking semantic heading tags. The report includes a visual outline of the current heading tree alongside a recommended corrected structure.