How to Fix NVDA Reading Errors in Tagged PDF Tables
Question details
The NVDA screen reader reads table column numbers and cell values as a single continuous number in tagged PDFs, lacking a necessary pause.
- Product
- PDF Reader/Editor
- Device & OS
- not provided
- Scenario
- Reading a tagged PDF table using the NVDA screen reader for accessibility purposes.
- Observed behavior
- NVDA announces table values incorrectly by merging the column number directly into the cell value without a pause or separation.
Ensure you have the latest version of the NVDA screen reader installed and a PDF editor capable of modifying document tags and accessibility structures.
Adjust PDF Tagging and Table Structure
Review and correct the PDF's table tagging structure to ensure proper header associations and add spacing to the accessible text.
Screen readers like NVDA rely heavily on the underlying tag structure of a PDF to determine how text is read aloud. When numbers run together, it usually indicates missing structural boundaries or a lack of spaces in the alternative text properties of the tags.
Open your advanced PDF editor and navigate to the Accessibility or Tags panel to view the document's underlying tag hierarchy.
Ensure that the table uses the correct tag structure, including a parent <Table> tag, <TR> for Table Rows, <TH> for Table Headers, and <TD> for Table Data cells.
Check the properties of your <TH> tags to confirm they are explicitly scoped as Column or Row headers, which helps NVDA contextualize the data properly.
Right-click the problematic cell tag, open its Properties, and add a space or punctuation mark (like a comma) to the 'Actual Text' or 'Alternate Text' field to force NVDA to pause.
Create Properly Tagged PDFs with WPS Office
WPS Office allows you to create well-structured documents with formatted tables and export them as clean PDFs, reducing screen reader errors like missing pauses.
- 1. Open Source Document: Launch WPS Writer or Spreadsheets and open the original source document containing the table.
- 2. Format the Table Correctly: Ensure your table has clear column headers. If NVDA historically skipped pauses here, insert a deliberate space or invisible punctuation in the header text.
- 3. Export to PDF: Go to Menu > Export to PDF to generate a new, structurally sound PDF document.
Frequently Asked Questions
Why does NVDA ignore spaces between columns in my PDF?
NVDA relies on the underlying structural tags of the PDF rather than the visual layout. If the table cells lack proper structural boundaries or the actual text in the tags lacks spaces, the screen reader will read the data continuously.
Can I fix tagged PDF reading errors without a premium PDF editor?
Yes. The most reliable free method is to fix the table structure and add appropriate spacing in your original source document (like Word or WPS Writer) and export it as a new PDF.
What tags are required for an accessible PDF table?
An accessible PDF table must include a parent <Table> tag, <TR> tags for table rows, <TH> tags for column or row headers, and <TD> tags for the actual data cells.
