Headings Structure in PDFs — Complete Guide

In this tutorial, you will learn about Headings Structure in PDFs. We cover key concepts, practical examples, and best practices to help you master this topic.

Headings structure in PDF Accessibility means marking content elements with the correct heading level tags (H1 through H6) in a logical hierarchy, enabling screen reader users to navigate the document by jumping between headings and understanding the content outline.

What You'll Learn

You will learn how headings are implemented in the PDF tag tree, how to create heading structures from common authoring tools, how to inspect and fix heading hierarchy in Acrobat, and how headings improve navigation for assistive technology users.

Why It Matters

Screen reader users rely on heading navigation as their primary method of scanning a document. Without properly tagged headings, users cannot skip to relevant sections, and the document becomes a single continuous block of text.

Real-World Use

An insurance company publishes a 50-page policy document. Before heading tagging, a blind customer must listen to the entire document to find the claims section. After applying H1 for the title, H2 for each major section, and H3 for subsections, the user presses H to jump directly to "Filing a Claim."

Heading Hierarchy

flowchart TD
  A["H1: Document Title"] --> B["H2: Section 1"]
  B --> C["H3: Subsection 1.1"]
  B --> D["H3: Subsection 1.2"]
  A --> E["H2: Section 2"]
  E --> F["H3: Subsection 2.1"]
  F --> G["H4: Sub-subsection 2.1.1"]
  E --> H["H3: Subsection 2.2"]
  A --> I["H2: Section 3"]

Creating Headings

From Microsoft Word

Use Word's built-in heading styles (Heading 1, Heading 2, Heading 3). When exported as a tagged PDF, these map directly to H1, H2, and H3 tags.

Document structure in Word:
- "Annual Report 2026" — Heading 1 style → H1 in PDF
- "Executive Summary" — Heading 2 style → H2 in PDF
- "Financial Highlights" — Heading 2 style → H2 in PDF
- "Revenue Breakdown" — Heading 3 style → H3 in PDF

Inspecting in Acrobat

Open the Tags panel. Headings appear as <H1>, <H2>, etc. in the tree. Verify that:

• There is exactly one H1 (the document title)
• No heading levels are skipped (H1 → H3 without H2)
• All visual headings have a corresponding tag

// Acrobat JavaScript to list all heading tags
var tags = this.getTags();
for (var i = 0; i < tags.length; i++) {
    var t = tags[i];
    if (t.structType && t.structType.match(/^H[1-6]$/)) {
        console.println("Tag: " + t.structType + " Text: " + t.getText().substring(0, 60));
    }
}

Fixing Heading Issues

If a heading is untagged, use the Touch Up Reading Order tool:

1. Select the heading text on the page.
2. Choose the appropriate heading level (Heading 1–6) from the tool panel.
3. Verify that the new tag appears in the correct position in the tag tree.

Common Mistakes

1. One H1 per page — A 10-page PDF should have only one H1 (the document title). Use H2 for top-level sections and H3 for subsections.

2. Skipping levels — Going from H1 to H3 without H2 creates a gap that makes the hierarchy confusing. Re-tag intermediate content to H2.

3. Using bold text instead of headings — Visually bold text is not a heading unless it has an H1–H6 tag. Apply heading tags to all heading-style content.

4. Over-tagging — Not every bold or larger text is a heading. Only tag content that serves as a section or subsection title. Callout boxes with fancy text should use <P> unless they are true headings.

5. Missing heading for each section — Every content section should have a heading. Tables, lists, and images without preceding headings lose context when navigated by heading.

Practice and Challenge

1. How many H1 tags should a single PDF have?
2. What is the problem with an H1 followed directly by an H3?
3. How does a screen reader user navigate by headings?
4. Which Acrobat tool can you use to assign a heading tag to untagged text?
5. What happens when a PDF has no heading tags at all?

Challenge: Take a 3-page PDF with at least 5 sections (some with subsections). Evaluate the heading structure. If there are issues, fix them. Export the tag structure as an HTML report and verify the heading hierarchy matches the document outline.

FAQ

Mini Project

Create a 4-page report in Word with a title (Heading 1), three chapters (Heading 2), and two subsections per chapter (Heading 3). Add a table of contents. Export as a tagged PDF. Inspect the heading tags in Acrobat and confirm the hierarchy matches your outline. Fix any discrepancies.

What's Next

Continue to Alt Text for Images in PDFs to learn how to add descriptions to images, then proceed to Accessible Tables in PDFs.