PDF heading levels
Silktide checks that the headings in your PDF documents follow a logical hierarchy, without skipping a level on the way down. An H1 should be followed by an H2 before any H3 appears, and so on.
Why this matters
People using navigate long documents by their headings, and use each heading's level to understand how the sections nest. When a level is skipped (an H1 followed directly by an H3), it looks as if a section is missing, and the document's outline no longer matches its structure.
How to fix it
- Fix it at the source where possible: use heading styles (Heading 1, Heading 2, Heading 3...) in order in the original Word, Google Docs, or InDesign document, then re-export as a tagged PDF.
- Alternatively, correct the heading tags in a PDF editor such as Adobe Acrobat Pro so that each heading is at most one level deeper than the heading before it.
- Use headings for structure, not for styling. Text that only needs to look bigger should not be tagged as a heading.
How Silktide tests this
- Open each PDF document found on your website.
- Read its heading tags in document order.
- Report the document if any heading is more than one level deeper than the heading before it (for example, an H1 followed by an H3).
Moving back up the hierarchy (from an H3 to an H2, or to an H1) is fine. Documents with no headings at all are reported by PDF headings instead.