Create accessible PDFs with InDesign

Keeping requirements in mind as you begin your design will make it much easier to export an accessible PDF, easier to remediate, and more user-friendly.

• Plan your paragraph styles early. In the final PDF, use one Heading 1 for your main title, Heading 2s for subheadings, Heading 3s for sub-subheadings and so-on. Additionally, you may use the headings to automatically generate a table of contents.
   
• Use styles to add space between paragraphs, not a hard return. A hard return creates an empty paragraph tag, which might be read out by a screen reader.
• To add a line break without creating a new paragraph or list item, use Shift-Enter.
• Anchor images in the content. You’ll want to place the images closest to where the information makes sense within the text. This will enable screenreader software to announce the image or graphic when it makes the most sense, and preferably not mid-sentence.

• You must map the paragraph styles to create the PDF tags that make PDFs accessible. Go to Paragraph Style Options dialog → Style Options → Export Tagging, then select the PDF Tag to apply to the Paragraph style currently selected. You will need to do this separately for each Paragraph Style.
  
• InDesign doesn’t offer all of the possible PDF Tags. For this reason, any text that falls outside these options should be remediated in Acrobat Pro or a comparable system. (Examples include caption, blockquote, span, quote, reference, annot (annotation), and a few others.
• Per Adobe’s own guidance, “Tables and bulleted and numbered lists are recognized automatically in the export process and tagged appropriately.”
• To add alt text, right-click on the object, choose Object Export Options, choose the Alt Text tab, then select Custom and enter your alt text below.
• If you use AI-generated alt text, be sure to check it to make sure it makes sense, and is useful and accurate. Be aware that if you don’t add alt text, InDesign may allow AI to automatically do it for you.

• Next, use the Articles panel to identify what elements should be tagged and in what order. To do this, drag items into the panel, then make sure the reading order is correct.

• Go to File → File info and add metadata. You must include a document title for accessibility.

• If your document is 8 pages or longer, you must include a linked table of contents, or minimally, PDF bookmarks. Shorter documents may benefit from a table of contents as well, so it is recommended for both accessibility and usability for some documents under 8 pages.
  
  Use InDesign’s TOC tool (under Layout menu) and TOC style options. This should create a correctly tagged table of contents. In the options, check “create PDF bookmarks" and “make text anchor in source paragraph,” which will ensure your TOC items are linked.

• When your PDF is ready, use the Export option, then choose PDF (Interactive), then be sure to:

  • Under Options, check the box for “Create tagged PDF” and

  • Under Options, check “Use Structure for Tab Order”

  • Note: If you export with different settings or save using PDF presets, you will need to make other adjustments in Acrobat Pro (see Specify the Tab order in Adobe’s guidance.)

1. Specify the document language in the advanced options of Document Properties
2. Also in Acrobat Document Properties, change the display name from filename to document title.
3. If you included page numbers (even if added correctly via Type → Insert special character → Markers → Current page number), be aware that they will be tagged with <p> paragraph tags, causing them to be read by a screenreader along with the text. (They may also be incorrect in the reading order.) To prevent them from being read, you should go into Acrobat Pro and mark them as artifacts. Click on the number, right-click → Change Tag to artifact. Then delete the empty container <p> tag and <sect> tag.
4. Check the reading order, which is determined by the order in the Tags panel (NOT the Order panel, as one might assume).
5. Check your headings. Sometimes if a heading has a line break, it will be split into two separate tags. When this happens, you need to move all of the text into the same heading tag. Otherwise, a screenreader will announce the heading level, read the first line, announce the heading level again and then read the 2nd line. This is annoying. The easiest way to fix this is to remove the line break in InDesign and re-export the PDF. Otherwise, you'll have to manually fix the tags in the Tags panel and the Content panel. (screenshot)
   
6. Optional, but recommended: Remove empty <p> paragraph tags. Tip: Click on the down arrow next to <Art> tag near the top of the Tag tree. Then, hold Shift-Ctrl and click the arrow again. This will open up all the levels of the Tag tree. Look for empty <p> tags, select them, and then delete them.
7. If your document contains image captions, table legends, complex tables, endnotes, footnotes, or pull-out quotes, these elements must be remediated in Acrobat Pro (or a similar system).

Note: PDFs created from InDesign documents tend to have a lot of <Sect> tags containing content chunks, which is fine. It doesn’t affect anything for the end user. They also have a large number of <span> tags which can be annoying if you like a tidy tag tree, but the consensus is that they have no effect on assistive technologies, so you can ignore them.

• If you used endnotes, the links in the text that link to the endnotes will work correctly. But the endnotes will also have links applied by InDesign which don’t function correctly.
• In practice, the table of contents (TOC) may not link to the correct places in your document. PDF bookmarks tend to work better and may allow the document to meet the WCAG requirement in stead of a linked TOC. But if your document has a linked table of contents, it must function correctly.
• Images with captions
• Complex overall design (multiple rows, images, graphics, endnotes, etc)
• Complex tables with merged cells or multiple header rows
• Your document is a form