The Logical Flow
- What: Reading order is the sequence in which assistive technology (like screen readers) navigates and announces the elements on a page. In a PDF, the “Reading Order” is determined by the Tag Tree. Tags are hidden labels that tell assistive technology, “This is a Heading,” “This is a Paragraph,” or “This is an Image.”
- Why: Humans read visually (top-to-bottom, left-to-right). Computers read based on the order objects were added to a file or how they are layered in the “Tag Tree.” If you add a title last, a screen reader might read it last—even if it’s at the very top of the page. Even if a document looks perfect visually, it is just a “flat image” to a screen reader unless it has a logical tag structure.
Accessible Writing Tip: Avoid Directional Language
Accessible Writing Tip: Avoid Directional Language
When writing content, avoid using “spatial” or “directional” references to guide the reader. If the reading order or the screen size changes (like on a mobile phone), those directions may no longer be accurate and not every reader can “see” what direction you are referring to.
- Bad: “Refer to the chart on the right to see the data.” (On a mobile phone, that chart might actually be below the text.)
- Good: “Refer to the Enrollment Trends Chart to see the data.”
- Bad: “Click the green button in the sidebar.” (A screen reader user might find the button, but they won’t know it’s green or that it’s in a ‘sidebar’.)
- Good: “Select the ‘Register Now’ button.”
By naming the elements specifically rather than describing their location, you ensure that your message remains clear no matter how a user “views” or “hears” the page order.
Print to PDF Trap
The #1 cause of reading order issues in PDF documents is using “Print to PDF.”
- The Problem: Printing to PDF “flattens” the file, stripping away all your Headings, Alt Text, and Link tags, creating a document with zero tags.
- The Solution: Always use “Save as PDF” or “Export to PDF” from your source document (Word, Google Docs, or Canva). This carries your hard work over into the PDF Tag Tree automatically.
- Review Export to PDF page for additional guidance.
How to Check Reading Order in a PDF
The most reliable way to check a PDF is to look at the Accessibility Tags Panel in Adobe Acrobat Pro.
Open the Accessibility Tags Panel
- Go to View > Show/Hide > Navigation Panes > Accessibility Tags.
- Click through the list of tags (e.g., <H1>, <P>, <Figure>, <Link>). As you click through the accessibility tags, Acrobat will highlight the corresponding content on the page.
Verify the Sequence
As you review the accessibility tags, ask yourself:
- Does the highlighted content move from top-to-bottom and left-to-right?
- Is all the content represented in the tags?
- Is the sequence for callouts, sidebars, and pullquotes logical?
If the highlighted content jumps around, is difficult to follow, or is missing content, your reading order is broken.
How to Fix the Reading Order
If your tags are out of sequence, you can rearrange them without changing the visual look of the document:
- Drag and Drop: In the Accessibility Tags Panel, simply click and drag a tag to its correct logical position in the tree.
- Reading Order Tool: If you see tags for decorative lines, background shapes, or page numbers, you can use the Reading Order tool to change these to artifacts to hide them from screen readers. From the Tools select Accessibility > Reading Order. Either select the accessibility tag or highlight the content in the document you need to change to an artifact and select Background/Artifact. Repeat as needed.
Caution: When to Fix vs. When to Go to the Source
Before you spend hours rearranging tags in Adobe Acrobat, assess the damage. Fixing the reading order in a PDF is a “post-processing” step; it doesn’t fix the original file.
Fix in Adobe Acrobat
Fix your reading order in Adobe Acrobat only if:
- You only need to move 1 or 2 items (like a misplaced page number or a decorative line).
- You no longer have access to the original Word, Google Doc, or Canva file.
- You are only “Artifacting” a few decorative elements.
Go Back to the Source File
Fix the reading order in your original source file if:
- The Tag Tree is empty: If you see “No Tags Available,” it means the file was likely “Printed to PDF.” It is 10x faster to “Save as PDF” correctly from Word than to tag a document from scratch in Acrobat.
- Tables are broken: Fixing table headers and merged cells in Acrobat is highly technical and prone to error. Fix them in Word or Excel and re-export.
- The order is completely scrambled: If every paragraph is out of sequence, your “Layers” or “Styles” in the source file are the problem. Fix them there to ensure any future versions of the document are also accessible.
Pro-Tip
Think of the PDF as a “printed” version of your work. If you find a typo on a printed page, you don’t use white-out and a pen on 100 copies; you fix the digital file and print it again. Treat accessibility the same way!