Creating Accessible PDFs

In addition to adhering to best practices for plain language, font, colour, and other accessibility essentials, an accessible PDF is tagged. PDF tags are code that provides structure for assistive technology.

To create accessible PDFs, ensure you have Acrobat Pro DC installed on your device. Acrobat Reader lacks the necessary features to make PDFs accessible. PDFs can be generated in software such as Adobe Acrobat, but the most common method is to take an existing Word document or PowerPoint presentation and export it to PDF. Ensure that you start with an accessible document before exporting to PDF.

PDFs are popular but may not always be the best choice of file. PDFs are an antiquated format that are extremely time consuming to make accessible. Consider providing HTML, Word, or PowerPoint (most documents can have editing restricted) first. If readers prefer PDF, they can convert your file to PDF.

The best way to use PDFs is sparingly.

On this page:

• PDF Source Documents
• Making Accessible PDFs
• Reading Order
• Check Accessibility
• Further Reading

PDF Source Documents

The majority of PDF documents will be converted from a Word or PowerPoint document. Refer to previous chapters for best practices to create accessible documents in those formats and ensure you properly export the file to PDF.

Office Software with Acrobat Installed

Scanned PDFs

PDFs are a common output format for scanned documents. A scanned document will be a ‘flat’ PDF—essentially an image of the scan. PDFs creating this way are untagged and not accessible.

Before scanning a document or book, consider looking for an existing accessible electronic version of your resource. However, when scanning a document to PDF:

• Set scanner settings to at least 300 DPI (dots per inch).
  • Higher number is better but increases the size of the scanned file.
• Scan in black and white or 24-bit colour.
  • Consider that information should not be conveyed by colour alone.
• Some scanners have built-in Optical Character Recognition.
  • You can tell if your scanner has this feature if you see terms like “Searchable PDF” or “Text PDF” in the scanner file output settings.
• Push the spine of a book as flat as possible to eliminate gutter distortion and missing text.
• Keep each scanned page to its own electronic page.
  • Do not scan two pages of a book at once.

Ensure scans are free from:

• Cut off text.
• Crooked pages.
• Shadows from the curvature of a book’s spine, dark gutters between pages.
• Poor contrast.
• Pages rotated 90 degrees or upside down.
• Handwriting, highlighting, underlining, watermarks or stains.
• Blurring.

Use Optical Character Recognition:

Run OCR on scanned documents as a first step toward creating accessible PDFs. To do so in Acrobat Pro:

1. Open scanned PDF in Acrobat.
2. Select Scan & OCR from Tools.
3. Select Enhance Text.
4. Select Recognize Text to amend the document or repair any text not automatically detected.
   1. Select Tools > Edit PDF.
   2. Select text elements and edit text as appropriate.

From Webpage

When wanting to save a permanent copy of a website, do not use Print to PDF or Print > Save to PDF.

At this time there is no way to directly create an accessible PDF copy of a webpage, even if the page itself is accessible. Currently, we recommend using PrintFriendly as it creates tagged PDF files when exporting a webpage to PDF.

To use PrintFriendly, install the browser extension or paste the URL in the PrintFriendly web interface, then select PDF. This will download a PDF copy of the webpage to your device. The PDF copy will still need to be evaluated and remediated to ensure it is accessible.

Another option for saving a PDF of a webpage is to use the Internet Archive’s Wayback Machine or Archive Today to create permanent copies of a webpage as it appears at the time of saving. Zotero saves a permanent copy of webpages when possible and allows for sharing, although readers need Zotero installed on their device.

Making Accessible PDFs

Use the following resources to make PDFs accessible.

1. If starting from a scanned document, use the Scan and OCR tool.
   1. Select Recognize text and choose in this file.
2. Open the File menu, choose Properties.
   1. Navigate to the Description tab.
   2. Enter a descriptive title.
   3. Move to the initial view tab and select Document title in the Show menu.
   4. In the Advanced tab, choose a language for the document.
3. Open the Tags pane and arrow through the tags tree.
4. Select the Reading order pane to show an overlay number on each object.
5. Select the Page thumbnails pane, select all pages, right click and select Page properties.
   1. Ensure Use document structure is selected under tab order. Click OK.
6. Place your cursor at the beginning of the document and press Tab to verify tab order.
7. Run the Accessibility checker.

Remediating PDFs can be difficult and time-consuming. Some people do this work full-time and still encounter difficulty. Please contact assistivetech@langara.ca for more information about remediating PDFs.

Reading Order

One of the most important elements requiring manual checks is the reading order of your document.

Save your file before making any changes to the Order, Content, or Tags panes. Verify changes to the Order pane visually and on the Tags pane. Be aware that when changing the reading order of items in the Order pane, some content may “disappear” (YouTube video, opens in new tab) behind other content.

To solve this issue:

1. Open the Content Pane (View > Show/Hide > Navigation Panes > Content).
2. The top of the list is the bottom visual layer of the document.
3. Selecting an element in the Content pane highlights the item in the document.
   1. So, if text disappears behind a textbox for example, locate both the text and textbox.
   2. Click and drag–or cut and paste–the offending item to the top of the list.
   3. This should return the visual order to normal.

Verify Reading Order:

1. Open the Tags Pane (View > Show/Hide > Navigation Panes > Tags).
2. Select the first tag at the top of the list.
   1. Use the down arrow to move through the list.
      1. You will see a visual highlight in the document when selecting each tag.
   2. If you need to re-order the reading order, cut and paste the tag (we find clicking and dragging can be difficult in longer documents).
3. Navigate to the Order Pane.
   1. Select Options.
   2. Select Show Reading Order Panel.
      1. This displays a number on each page element representing it’s reading order.
   3. Open the Content Pane.
      1. Arrow from top to bottom of content list.
      2. Verify that the visual order matches the reading order.

Check Accessibility

After you remediate your PDF, run the Accessibility Check tool again:

1. Open PDF in Adobe Acrobat Pro DC
2. Expand the Tools Pane
   1. If you do not see the Tools Pane, select View > Show/Hide and click Tools Pane
3. Click Accessibility
   1. If you do not see Accessibility, select More Tools, scroll down and select Accessibility
      1. Recommend to open menu and select Add Shortcut for future use
   2. You can also search for tools at the top of the Tools Pane
4. Click Accessibility Check
   1. Click Start Checking
      1. The Accessibility Pane will open and show accessibility issues. Right-click to see further explanation and/or fix the issue directly

Video demo:

Use Reflow or Export to Text export to verify accessible reading order.

1. Select View > Zoom > Reflow,
   1. As you zoom in, content should reflow into a vertical column with no need for horizontal scrolling,
2. Many PDFs will not reflow. Check the order of text via File (Acrobat on macOS) menu and select Export To > Text (Accessible). Save the file and view what text content is exported and how it is ordered. That is what and how assistive technology will read to a user (absent any interactives such as forms and image alternate text).

Use Preflight tools to correct remaining tagging issues:

1. Navigate to Tools > Print Production > Preflight,
2. Select PDF Profiles,
3. Expand PDF/UA,
4. Select Fix problems in PDF tagging structure,
5. Click Analyze and Fix,
6. Save new copy.

For advanced accessibility checks, use PAVE (online) or PAC 2021 (Windows only).