PDF headings
Silktide checks that your PDF documents contain headings in their accessibility structure. Headings give a document an outline that people and software can navigate, rather than a single unbroken stream of text.
In a , headings are marked with heading tags (H1, H2, and so on), just like headings on a web page. Text that is merely styled large and bold is not a heading to software - only the tag makes it one.
Why this matters
People using navigate long documents by their headings: pull up the list of headings, jump to the section they need, skip the rest. In a document without heading tags, that list is empty - the only way through a fifty-page report is to listen to it from the beginning. Headings also power the document outline shown in PDF viewers, so everyone benefits from them.
How to fix it
- Fix it at the source where possible: apply real heading styles (Heading 1, Heading 2...) in the original Word, Google Docs, or InDesign document, then re-export as a tagged PDF. Heading styles become heading tags automatically.
- Alternatively, tag the headings in a PDF editor such as Adobe Acrobat Pro: mark each visual heading with the appropriate heading tag, keeping a sensible hierarchy (H1 for the title, H2 for sections, H3 for subsections, without skipping levels).
- If the document has no tags at all, start there - see PDF structure tags.
How Silktide tests this
- Open each PDF document found on your website.
- Look for heading tags in the document's accessibility structure.
- Report the document if it contains no heading tags at all.
Note that this check looks for the presence of headings, not their hierarchy - a document with headings in an illogical order will still pass, so review the outline when you tag it.