Portable Document Format (PDF) has become a ubiquitous medium for sharing documents in various settings, from educational materials to business reports. Ensuring the accessibility of PDFs is crucial to provide equal access to everyone. In this article, we will explore key considerations and best practices for creating accessible PDFs.
PDF accessibility still uses the basics  of accessibility so we will not cover all of the things that make a PDF accessible but some of the unique things to watch out for in PDFs.

Document Structure and Headings

Layers of a PDF

There are 3 layers in a pdf, the visual layer, the content layer, and then the tags layer.  The visual layer is considered to be exactly what you visually see.  the visual layer should be identical to our source document (i.e., word, PowerPoint, etc.).  The content layer is the formatting of the document itself.  This includes things like color, lists, tables, forms, and the reflow of the document.  the last layer is the tags layer.  This layer is the actual semantic markup that is used in the document.  This information is needed so that assistive technology users can interact and read a pdf.  When we talk about accessible pdf's we primarily focus on this tags layer because that is what is missing in pdf's most of the time. 

When we use settings word like the inline text option to change the document flow or layout this can create accessibility barriers for certain individuals if we do not fix them in the pdf.  The inline text option allows text to be to the side of an image or object or have the object be behind the text.  Objects that are being floated should only be for decorative purposes and NOT be conveying meaning to the user of any kind.  A lot of times these objects will need to be removed from the flow by marking them as decorative in order for the screen reader to be able to navigate them appropriately which is the same as headers and footers.  Note that with Equidox we have more flexibility here but it will take additional time to make accessible. 

Logical Reading Order

Establishing a logical reading order is fundamental for PDF accessibility. Screen readers navigate content based on the reading order, so it's essential to structure the document in a way that makes sense when read linearly. Use the correct heading tags (H1, H2, etc.) to create a hierarchical structure.

Document Language and Title

Specify the document language to ensure accurate text-to-speech conversion for users relying on screen readers. Additionally, provide a meaningful and descriptive title for the document to give users a clear understanding of its content.

Headers and Footers

Headers and footers are in this same boat because headers and footers are typically not made accessible for users when converted to a PDF which means users that have visual disabilities will not be able to access the footer or header content.  However, it should be noted that there have been great strides made in this area to make them more accessible.

Text and Fonts

Contrast and Font Size

Maintain a high contrast between text and background colors to enhance readability. Choose fonts that are clear and easily distinguishable, and ensure that the font size is adjustable to accommodate users who may need to zoom their screen in.  Our font should not be less than 12pt anywhere in the document, but larger font is usually better if it is possible.

Alternative Text for Images

Include descriptive alternative text for images and graphics within the PDF. This allows users of assistive technology to understand the content conveyed by the visuals. Most PDF authoring tools provide options to add alt text to images.

Hyperlinks and Navigation

Descriptive Hyperlink Text

Instead of using generic terms like "click here," use descriptive text for hyperlinks that conveys the destination or purpose of the link. Assistive technology such as Screen readers, provide users with a list of links, and meaningful link text enhances navigation.

Table of Contents and Bookmarks

For longer documents, create a table of contents and include bookmarks. These features assist users in navigating to specific sections efficiently, improving the overall user experience, especially for those with cognitive disabilities.  Make sure that these are linked properly and make sense based on where the link is going. 

PDF Elements

Accessible Form Fields

When creating forms in PDFs, ensure that form fields are properly labeled and have associated text. Assistive technology uses this information to guide users through form completion. Additionally, provide instructions and alerts for any errors in form submissions.  

Interactive Elements

If your PDF contains interactive elements such as buttons or form fields, make sure they are accessible. Assign proper names, roles, and descriptions to interactive elements, ensuring that all users can engage with the content seamlessly.

Tables

Every table should have at least 1 header in it.  If there is no way to use a header then consider a different way to visually display your content so that it is accessible for all of your users.  

PDF Testing and Validation

Accessibility Checking Tool

Utilize accessibility checking tools to identify and address potential issues within your PDFs. Adobe Acrobat, for example, provides an accessibility checker that can highlight areas needing improvement and suggest corrections.

Here at UVA we use Equidox to help remediate, or correct, barriers in our PDF’s to ensure that they are accessible.  Contact the CACS team or the Digital Accessibility Coordinator today to get signed up for this free service and get trained.

User Testing

Run your PDF through Equidox and Adobe Acrobat Pro (if available) to gather feedback on the accessibility of your PDFs. This practical approach helps uncover real-world usability challenges and ensures a more inclusive design.  When possible use a screen reader to interact with the pdf to see where additional barriers maybe as well. 

Conclusion

Creating accessible PDFs is a crucial step in promoting digital inclusivity. By adhering to best practices in document structure, text and fonts, hyperlinks and navigation, forms and interactive elements, and thorough testing, content creators can contribute to a digital landscape where information is accessible to everyone, regardless of their abilities or disabilities. Embracing accessibility in PDFs not only aligns with principles of equity but also enhances the overall user experience for a diverse audience.