Creating Accessible PDFs

Steps to take

To make a PDF accessible:

  1. Run the Accessibility Checker
  2. Set the document language
  3. Tag your PDF
  4. Create bookmarks
  5. Use headings and lists
  6. Make your graphics and images accessible
  7. Check your colour contrast
  8. Check the logical reading order
  9. Create navigation links
  10. Make tables accessible
Run the Accessibility Checker

To run the accessibility checker on your PDF, you need to be using Acrobat Pro.

To run a PDF accessibility checker:

  1. Open your PDF and go to View > Tools > Accessibility > Open
  2. The Accessibility Checker will open in the task pane
  3. Select 'Full Check'
  4. After the check has run, the results will appear in the Accessibility Checker panel
  5. There will always be at least 2 issues identified by the Checker: ‘Colour Contrast’ and ‘Logical Reading Order’. That is because these issues need a human to review them

Resource: Using the Accessibility Checker (YouTube tutorial)

Set the document language

The document language helps screen readers know what language they're reading in. To set the language:

  1. Select File > Properties
  2. Select the  ‘Advanced’ tab
  3. Under ‘Reading Options’ choose the correct language from the 'Language' drop-down list
Tag your PDF

Tags provide a logical structure that governs how the content is presented through assistive technology.  

To create tags in your PDF:

  1. Open the ‘Order’ tab in the Accessibility Checker
  2. Open 'Options' > Reading Order Panel
  3. Open 'Single Page View' from the top navigation to help you be more accurate in your tagging: View > Page Display > Single Page View
  4. Open ‘Zoom to Page Level’ from the top navigation: Zoom > Zoom to Page View > Zoom to Page Level
  5. Highlight text by double clicking on text or drawing a rectangle around it with your mouse. Once it is highlighted, select the appropriate tag from the 'Reading Order Panel' ('Heading 1' for the title of the document, text/paragraph for each paragraph, 'Heading 2' for each section title, Heading 3' for sub-titles, Figure for graphs and images)
  6. If you have any decorative content, tag these as ‘Background/Artifact’
  7. Repeat this process on each page of your document

Resource: Tagging your PDF (YouTube tutorial)

Create bookmarks

A bookmark is a type of link that goes to a specific place or page in your document. If your document is longer than 21 pages, it must have bookmarks to pass the accessibility checker. To create bookmarks:

  1. Open the ‘Bookmarks’ tab in the Accessibility Checker panel
  2. Open the page where you want the bookmark to link to
  3. Highlight the area of the page you want to bookmark. The selected text becomes the label of the new bookmark. You can edit the label
  4. To bookmark an image, click on the image or drag a rectangle around it
  5. New bookmarks are automatically added to the end of the bookmark list. You need to drag and drop your bookmarks into the correct order
  6. Sub-headings can be nested under bookmarks by indenting them in the list

Resource: Creating Bookmarks (YouTube tutorial)

Use headings and lists

People and assistive technologies scan written content for headings. Headings let you know if the information is relevant to you.

To make headings and lists accessible:

  • Give your document a title using the ‘Title’ tag at the start of your document
  • Break content into manageable chunks with ‘Heading 1’ (H1)
  • Create sub-headings using ‘Heading 2’ (h4)
  • Sub-sub headings should be ‘Heading 3’ (h5)
  • Keep headings short
  • Use keywords
  • Use sentence case for headings 
  • Use bullet point lists to make content easier to scan. Only use numbered lists to show ordered steps

Resource: Microsoft’s video on improving heading accessibility (external link)

Using images

Visual content includes graphics, images, pictures, SmartArt, shapes, groups, charts, embedded objects, ink and videos.

Alternative text (alt text) helps people who cannot see the visual content understand the context of it. When writing alt text, think how you would describe the image to someone over the phone.

To create alt text:

  1. Right click on the image
  2. Select ‘Edit Alt Text’
  3. Write a short description of the image (5 to 10 words)

If the image you're using is decorative and does not convey any additional information, select the ‘Mark as decorative’ check box.

To find all instances of missing alt-text use the Accessibility Checker.

Check the logical reading order

The Accessibility Checker will flag ‘Logical Reading Order’ when you run it. That's because it needs a human to review the order to make sure it's logical. The tagged order should follow the same flow that a sighted person would use. In most cases this means, left to right and top to bottom.

To check the logical reading order:

  1. Open the ‘Tags’ tab in the Accessibility Checker
  2. Select the first tag. This should be the title of your document. There should only be one title tag per document. When you select the tag, a rectangle will appear around the content that it represents in the document
  3. Use the ‘down arrow’ button to move to the next tag. This should move the rectangle to the next content you would logically read on the page, (for example: the first paragraph)
  4. If the rectangle skips content, you may need to create a tag or reorder the tag
  5. To create a new tag, highlight the text or image that you want to tag. Select ‘Create Tag from Selection’ from the options menu. Select the ‘type’ of content it is (for example: paragraph, link)
  6. To reorder tags, open the ‘Tags panel: on the left side of your screen. Drag and drop the tags into the correct order
  7. If the rectangle lands on a decorative item, such as a bar dividing sections, select the item, and then select ‘Change Tag to Artifact…’. Select ‘Page’ from the 'Artifact' menu. Then delete the tag. This will stop a screen reader from reading it out loud to the user
  8. Once you've placed the tags in the correct order, go back to the beginning of your document and hit the down arrow until you reach the end of the document to ensure the tags follow the intended flow

Resource: Using Logical Reading Order (YouTube tutorial)

Create navigation links

Hyperlink keywords that describes where the link goes. For example:

  • Do not use: Click here to read the traffic report
  • Instead use: Read the traffic report

Add 'ScreenTips' that provide a description when your cursor hovers over a hyperlink.

To add 'Screen Tips':

  • Select: File > Options > General > ScreenTips Style > Show Feature Descriptions in 'ScreenTips' > OK

Resource: Microsoft’s video on creating accessible links (external link)

Resource: Creating Navigation Links (YouTube tutorial)

Make tables accessible

Just because a table has been tagged does not meant it's accessible. Tags need to indicate which cells are headers and which cells are data. To do this you need to check to see how individual cells are tagged:

  1. Open the 'Reading Order' tool
  2. Select the table, then select 'Table Editor' from the 'Reading Order' tool
  3. Right click on the table to open the 'Table Editor Options'
  4. Check the 'Show Cell Type' checkbox, and then select 'OK'

To add header cells:

  1. Right click on a header cell and select 'Table Cell Properties'
  2. Change the type from 'Data Cell' to 'Header Cell'
  3. Identify if the header is a row or a column by choosing one from the 'Scope' dropdown menu

Resource: PDF Accessibility: Tables (YouTube)