Acrobat and Accessibility
Adobe Acrobat Professional is the most commonly-used program to evaluate, repair, and enhance the accessibility of existing PDF files. This article outlines accessibility features and best practices in Acrobat DC and XI.
Set Up Acrobat
The two most important tools for reviewing and repairing PDF accessibility are the Tags pane and the Accessibility tools pane. They are both hidden by default in Acrobat, so you will need to go through a one-time process to make these tools visible and available.
To open the Tags pane for the first time, select.
The Tags pane will appear in a sidebar on the left side of Acrobat. To show or hide this pane in the future, click the "Tag" icon in on the far-left side of the window.
To show the Accessibility tools pane for the first time, click thetab in the upper-left of the window (not the Tools pane on the right side). In the search bar below the tab, enter the word "accessibility". When the tools appear, click the button.
Go back to the PDF you are working on and you will now seein the right-hand sidebar. Click it to open a group of accessibility tools.
To show the Accessibility Tools for the first time in Acrobat XI, open themenu ( ) in the upper-right corner of the Tools sidebar and select to make it visible, then click to expand this section.
You will likely move between the Tags pane and accessibility tools multiple times while repairing a PDF.
Reading Order Tool
The Reading Order tool—called Touch Up Reading Order (or TURO) in older versions of Acrobat—helps you add and edit many common PDF tags. To use this tool, go to thetools and select (or in Acrobat XI). A dialog will appear.
The appearance of the PDF also changes—the content will become encased in numbered gray boxes.
If you don't see any boxes, your PDF document is most likely untagged.
View "Structure types"
By default, each of these gray boxes are numbered to represent the content order of the PDF, but it is best to worry about the structure of the PDF first, then its reading order. To see the tag structure instead, choose theradio button in the dialog.
This will change the view so that the white boxes in the upper left corner of each element displays the tag type (e.g., "P" or "H1") instead of the numbers.
Add & Change tags
You cannot undo changes made with the Reading Order tool. Save often!
To add or change a tag, use the crosshairs () to draw a box around content you want inside this tag. It is sometimes difficult to select exactly the right area, but it is a little easier if you try drawing a box that is slightly larger than the content. If there is already a gray box around the element, and you just want to change the tag (e.g., changing a heading level), try clicking on the tag in the top-left corner of the box. This should select the box, but the behavior can be a bit buggy. You will probably need to switch between these two techniques while repairing a PDF.
After selecting the area, choose the desired tag from the Reading Order window.
|Button||PDF Tag||Additional information|
(Text in XI)
||If you select the image and adjacent text, then the image will be tagged as a figure and the text will be tagged as its caption.|
||Acrobat attempts to assign rows, columns, and headings. Sometimes it does this correctly, but this should still be checked with the table inspector.|
||Can be used to merge cells if they are incorrectly split.|
(Background in XI)
|Artifact||This will hide an item completely from a screen reader. It can be used on images and text.|
If you do not see an option for your desired tag, you will need to create it manually in the Tags pane.
It is often best to remove existing tags a specific item or area before assigning new ones, especially for buttons that create multiple tags like "Table." To remove the structure from an area on the page, select it as outlined above,, and select . To clear an entire page, select the button in the tool dialog. You can then select items and assign the proper tags.
When an image is tagged as a figure, the alternative text will appear in a black box in the upper-left corner of the image. If it has no alternative text, the caption will read "Figure - No alternate text exists."
To add or edit alternative text, appropriate alternative text in the dialog box.on the image and select . Enter the
You may be able to use the Reading Order tool to hide or show text within complex images like charts. For example, if the text in a bar graph is being read by a screen reader when it should be ignored, draw box around the entire chart and select thebutton. Conversely, if the percentages in a pie chart are being ignored when you want them to be read, try drawing a box around each bit of text and tagging it with the button.
The Table Inspector allows you to easily identify, create, and repair table headers.
With the Reading Order tool open, select a table and then select. Click and drag to select a group of the column or row headers. on the selected cell or cells and choose .
A dialog box will appear. Select theradio button, then select the menu and choose or (never choose "Both" or "None").
After selecting, you will notice that the table header cells are highlighted in red and the data cells will be highlighted in gray. Repeat for all the headers in the table.
Tables with more than one level of row or column headers, or with cells that span multiple rows or columns, may need extensive work to ensure they are presented correctly to screen readers. Whenever possible, simplify your tables to avoid this overhead. If the table structure is very poor, it may be easier to have Acrobat re-tag the table automatically. Click outside the table to exit the Table Inspector, then select the, and choose . Draw a box around the entire table and select the button. The quality of the tags for a table can vary greatly—Acrobat does best when the table has clear borders between each cell and no background colors.
Repair the Content and Tag Order
If you made changes to the tag structure of the PDF, you need to make sure the tag order is correct. It is natural to assume that the Reading Order tool is the place to fix this, but it is actually much more complicated than that.
Review and repair the content order
To review and repair the content order, open thetool and select the radio button. The tags in the upper-left corner of each content box will change back to numbers. If the order of these numbers is not correct, select the button and Acrobat will open the Order pane on the left side of the window.
To change the content order, either click-and-drag the items listed or use the cut and paste keyboard shortcuts—Ctrl (or Command on Mac) + X or V.
Using this page can be confusing. While it displays the content order (not the tags order), changes made within this panel will be reflected in both the tags and content order, but this behavior can be unpredictable. It can cause discrepancies between content and tags order, and even break order that was previously correct, so changes made in thepane should be completed first and then verified in the pane.
Other Tools and Features
The built-in accessibility checker "Full Check" is a good tool to use with a new PDF to identify what issues need to be addressed, and after repairing a PDF to ensure no obvious issues were overlooked. To run the checker, selectfrom the Accessibility tools pane. The results will appear in the "Accessibility Checker" Pane on the left side of the window.
For additional information about an issue,it and select , and Acrobat will direct you to online documentation that outlines the issue, and often tells you how to fix it.
The Accessibility Checker cannot identify all accessibility issues. You should also manually check the document for other potential issues.
Set Alternate Text
To add alternative text to multiple images, go to thetools and select . The first image in the file will be highlighted, and a dialog box will appear with a space to enter the alternative text. Enter the appropriate alternative text and press the to move to the next image.
There is also a checkbox to identify an image as a Decorative figure. Unfortunately, this feature does not work as it should. If you check this box and run the Accessibility Full Check again, the error for the image will change from "Figures alternate text - Failed" to "Other elements alternate text - Failed." Until this bug is resolved, do not use this checkbox to hide decorative images. Instead, skip over these images by pressing the right arrow button to skip to the next image. After adding alternative text to all the images that need it, select. Then use the button in the Reading Order tool to hide any images that should not be read by a screen reader.
Convert Scanned Text
Before you can create a tagged PDF, you must first ensure that the PDF contains real text. If it does not, you must either recreate the PDF file (if you have the source document) or convert it to include true text. To add this tool, go to the tab and find add . Return to the PDF, select in the Tools pane, then in the toolbar above the PDF, select .
The quality of the text depends on the clarity of the source document. To clean up any text that Acrobat had trouble detecting, select(called in Acrobat XI).
The Reflow view allows users to reorder the content of a PDF into a simplified, single-column layout, based on the content order.
Select Control + 4. If the document does not appear in the correct order while in Reflow view, fix this using the Order pane, as outlined above.or
"Make Accessible" Action Wizard
Acrobat Action Wizards automate common multi-step processes in Acrobat, including several common steps in creating an accessible PDF.
The "Make Accessible" action Wizard can be a useful tool, especially when starting with scanned or untagged PDFs. It is a helpful way to ensure that you don't miss any steps while making your document accessible, like providing a page title or document language. To run the wizard, use thetab to add (it should be visible by default in Acrobat XI), then Open and choose . The wizard will then run you through several steps:
- Add Document Description
- Set Open Options
- Recognize Text using OCR
- Detect Form Fields
- Set Tab Order Property
- Set Reading Language
- Add Tags to Document
- Set Alternate Text
- Run Accessibility Full Check
If your PDF is already tagged (e.g., you created a PDF using instructions on the previous page) you must skip step 3: "Recognize Text using OCR." Otherwise, your PDF will be re-tagged, and the new tag structure is seldom as good as the original. To skip this step, preferably before you start the wizard,the option and select .
You will still want to check your PDF after using this wizard. For a video walkthrough and handout on the "Make Accessible" Wizard, see the GOALS Acrobat cheatsheet.