How to Fix PDF Accessibility Tags Not Read Correctly by Screen Readers
Question details
The user is experiencing issues where screen readers do not properly read table alt text, bulleted lists are read as a single continuous sentence, and heading levels are announced incorrectly in a PDF document.
- Product
- Device & OS
- not provided
- Scenario
- Testing a PDF document for accessibility compliance using a screen reader to ensure users with disabilities can navigate the content.
- Observed behavior
- Screen readers ignore table alt text (relying instead on headers/cells), read bullet lists as one single sentence without pauses, and misidentify heading levels (e.g., H1 read as H2).
Ensure your screen reader software is updated to the latest version, as older versions may have bugs parsing PDF accessibility tags. You will need a capable PDF editor to inspect the document's hidden tag tree.
Inspect and Repair the PDF Tag Structure
Use the accessibility tag tree in your PDF editor to manually correct structural tags for lists and headings.
Screen readers rely heavily on the underlying tag structure of a PDF rather than its visual layout. If lists are read as a single sentence, the proper <L> (List) and <LI> (List Item) tags are likely missing or flattened into standard paragraph text.
For tables, screen readers prefer proper <TH> (Table Header) and <TD> (Table Data) cell relationships over general table alt text, which is why your alt text might be ignored.
Open the PDF in your advanced PDF editor and navigate to the 'Tags' panel or accessibility sidebar.
Locate the incorrect heading tags in the tree (e.g., an <H1> mistakenly tagged as <H2>). Right-click the tag, select 'Properties,' and change the tag type to the correct heading level.
Find the problematic bulleted list. Ensure it is wrapped in an <L> tag, with each item in an <LI> tag containing <Lbl> (Label) and <LBody> (List Body) tags. Create new tags if they are missing.
For tables, ensure the structure uses <Table>, <TR> (Row), <TH> (Header), and <TD> (Data) tags properly mapped to the cells, rather than relying solely on the table's Alternative Text property.
Regenerate the PDF from an Accessible Source Document
Instead of manually editing complex PDF tags, fix the accessibility structures in the original source document and re-export the PDF.
Create and Export Accessible PDFs with WPS Office
WPS Office provides comprehensive tools for creating structurally sound documents that export smoothly into tagged PDFs. With WPS Writer, you can ensure your headings, lists, and tables are formatted correctly from the start to prevent screen reader errors.
- 1. Create or Import Your Document: Open WPS Writer and open the source document you want to make accessible.
- 2. Apply Structural Styles: Select your text and apply structural styles like Headings, formatted Lists, and Table Header Rows directly from the Home and Table Tools ribbons.
- 3. Export to PDF: Go to the Menu and select 'Export to PDF'.
- 4. Retain Accessibility Tags: Ensure the export settings are configured to retain document structure and bookmarks, then save your highly accessible PDF.
Frequently Asked Questions
Why doesn't the screen reader announce my table alt text?
Most modern screen readers prioritize the internal tag structure of a table (like row and column headers) over the table's overall alt text. Ensuring your table has properly tagged <TH> and <TD> cells is more effective for accessibility than a general description.
How do I stop my bulleted lists from being read as one long sentence?
This happens when the list is exported as standard paragraph text rather than a structured list. You must verify that the PDF tag tree contains an <L> (List) parent tag containing individual <LI> (List Item) tags for each bullet.
Can I fix PDF tags without the original source document?
Yes, but you will need an advanced PDF editor to access and modify the hidden Tags tree manually. Because re-tagging complex documents can be incredibly time-consuming, fixing the source file and re-exporting is always recommended when possible.
