How to Make a PDF Accessible: Reading Order, Alt Text and Searchable Text
A global step-by-step workflow for creating more accessible PDFs and checking common screen-reader barriers.
Accessibility begins before export
A PDF can look polished on a laptop while remaining confusing to a screen reader. Headings may be indistinguishable from ordinary text, columns may be read in the wrong order, and important diagrams may have no alternative description. Accessibility is therefore not a decorative finishing step. It is a question of whether a reader can perceive the content, navigate it and understand the sequence. The most efficient workflow usually starts in the original word-processing or design file, where headings, lists and tables can be structured before the PDF is created.
Use real document structure
Apply the authoring application’s built-in heading styles rather than making text larger and bold manually. Use actual list tools for bullets and numbered sequences. Keep heading levels logical: a main section should not jump unpredictably to a deep subheading. Mark table headers in the source document when supported and avoid tables used solely to position text on a page. A clear structure improves both assistive navigation and ordinary editing. After export, inspect whether the PDF retained document tags rather than assuming a visual match means the structure survived.
Make text searchable and selectable
A scanned page is often just an image. A reader may be unable to select a sentence or search for a name, and assistive software may have no reliable text to read. Optical character recognition can add a text layer, but OCR output must be checked against the original. Pay particular attention to names, dates, equations and small print. If the source file exists, exporting clean digital text is usually preferable to scanning paper and trying to repair the result. Never assume a successful OCR operation guarantees accurate or accessible reading order.
Check the reading order
Reading order is the sequence in which assistive technology encounters text, images and form fields. Multi-column layouts, sidebars and floating callouts are common sources of errors. In a PDF editor with accessibility tools, inspect the tag structure and reading-order view. Read through the document as a user would: heading, introduction, supporting image, then the next paragraph. If a caption appears before the image it describes or a footer interrupts a sentence, repair the structure. Adobe’s documentation advises returning to the original authoring file where possible.
Write meaningful alternative text
Alternative text should communicate the purpose of a meaningful image, not merely announce that a picture exists. For a chart, explain the central relationship or finding and provide underlying data when the reader needs precise values. For a decorative flourish that adds no information, mark it appropriately as decorative or an artifact rather than forcing a screen reader to describe it. Avoid repeating nearby captions word for word. Good alt text is specific to the document’s purpose; the same photograph can require different descriptions in a training manual and a travel brochure.
Repair tables and forms
Simple tables should have an identifiable header row and logical cell sequence. Complex merged cells can make navigation difficult, so simplify where possible or provide an equivalent accessible explanation. For fillable forms, labels and instructions must be associated with the correct fields. A form that can be filled with a mouse but not understood through keyboard navigation is not fully usable. Check tab order and ensure required fields are explained in text. Test with the actual PDF viewer or accessibility tool your audience is likely to use.
Check links, language and contrast
Use descriptive link text that tells readers where a link leads, rather than relying on repeated generic phrases. Set the document language where the software supports it; this helps assistive technology interpret pronunciation. Ensure text has sufficient contrast against its background, and do not communicate essential distinctions through colour alone. A coloured warning icon should have an accompanying textual warning. Keep navigation aids such as bookmarks for long documents. These improvements help readers with varied devices, low vision and cognitive needs, not only screen-reader users.
Test a representative sample
Do not stop after an automated accessibility checker reports no errors. Open the PDF, try keyboard-only navigation, search for a phrase, inspect tags and read a sample with a screen reader if available. Test at least one heading sequence, a list, a link, an image and any complex table. Automated tools can find missing properties but cannot judge whether an image description is meaningful or whether a paragraph is logically placed. Document remaining limitations and repair the source file so future exports do not repeat the same problem.
Frequently asked questions
Does OCR make a scanned PDF fully accessible? No; text accuracy, tagging and reading order still need attention. Is alt text needed for every decorative image? No; purely decorative content can be marked as an artifact. Should I fix the PDF or its source file? Prefer the source when available. Does passing an automated checker prove accessibility? No; human review and assistive-technology testing remain important. Can an accessible PDF still look attractive? Yes; semantic structure and visual design can support each other.
Before you finish: a practical final check
Accessibility work benefits from an explicit review owner. Assign someone to check structure, someone to verify the accuracy of meaningful image descriptions, and a reader to test whether the document makes sense without visual cues. For recurring reports, maintain an accessible template rather than repairing every PDF from scratch. Keep the original editable file alongside the final PDF and record which application exported it. When a document is revised, rerun the checks because a newly inserted chart, sidebar or table can change reading order unexpectedly. Treat accessibility as a repeatable publishing practice.
