How to Create an Accessible PDF
Accessible PDFs are also known as “tagged” PDFs. They contain a hidden network of instructions and provide a textual representation of the document so that people using screen readers can properly navigate the document.
Properly tagged PDFs also benefit from better search engine optimization (SEO) because search engines read the words between header tags before anything else.
There are countless programs that enable you to save a document as a PDF. Not all of those programs, however, will produce tagged PDF files. There is also more to making an PDF accessible than simply adding tags.
Anatomy of an Accessible PDF
These criteria represent the basic features of an accessible PDF (source: Adobe).
1. Hierarchical Heading Structure and Logical Reading Order
The sections of your PDF must be organized so that screen readers know the difference between different sections (titles, section headers, subsection headers, and text body) and content like tables and sidebars.
Hierarchical heading structures follow a specific tagging structure:
<H1>is the main or title header, followed by
<H3>, and so on in descending order of importance. Below is an example of how screen-readers understand certain sections based on their tags.
2. Alternative Text Descriptions
Basically, any content in your PDF that is not just text (i.e. visual elements like images, form fields, hyperlinks, etc.) needs to be identified and described with what is called alternative text, or “alt text.” Alt text is read aloud by a screen reader and describes what an element looks like. Alt text is especially important for images that contain a lot of relevant information.
For example, here is a graph from our 2017 State of Captioning report:
And here is the alt text for the image that a screen reader would read aloud:
Column chart showing how captioning needs are perceived to change next year. 1.35% of survey respondents see their captioning needs decreasing next year; 25% see them staying the same; 35.98% see them increasing moderately; 37.68% see them increasing significantly.
3. Navigational Aids
Navigational aids include links, a table of contents, and anything else that enables a user to go directly to a particular point in the document, instead of reading it through page by page.
A table of contents works best when it accurately describes each section of the document and can send the user directly to the appropriate page when they click on a section header in the table.
4. Features that Do Not Interfere with Accessible Technlogy
Some documents have restrictions that serve to prevent certain actions like copying, extracting, or editing information within the document. It must be ensured that these features do not interfere with a screen reader’s ability to extract and read aloud any plain text from the underlying data of elements within the document.
5. Use Accessible Fonts
Some fonts do not work well with screen readers. If any of the characters cannot be converted by the screen reader to plain text then words or sentences will not be read allowed, rendering the document inaccessible. Fonts must also be able to pass a color contrast test.
How to Create an Accessible PDF of Your Video Transcript
Creating an accessible PDF is very simple in Word or Adobe. If you want to convert a video or audio transcript file (.txt, .doc, or .docx formats) into an accessible PDF, follow these instructions.
As long as you have the correct settings, Microsoft Word (2010 or higher only) will auto-tag your document when you save it as a PDF. This works on both Mac and Windows.
Note: This tagging process works well for simple text-only transcript files. For documents with more complicated content like tables, forms, and images, refer to these instructions for making accessible documents in Word and converting to PDF.
- Go to File > select Save As > select PDF (*.pdf) from the drop-down menu.
- Before clicking Save:
Mac: Select the radio button “Best for electronic distribution and accessibility (uses Microsoft online service).” Click Save.
Windows: Select More Options… from below the file format menu, then select Options from the Save window, and make sure that “Document structure tags for accessibility” is selected. Click OK and Save.
Note: If you have the Adobe Acrobat Add-in, all you need to do is open your file in Word, go to File , and select Save as Adobe PDF.
In Adobe Acrobat…
All you need to do is open your file in Acrobat, go to the Accessibility tool and select the Autotag Document option.
For more information about converting documents other than transcripts to accessible PDFs, visit WebAIM.