What’s the difference between a PDF and an accessible PDF?

A PDF (Portable Document Format) is a file format widely used for document exchange. It is a format that preserves the visual appearance and layout of a document, regardless of the software, hardware, or operating system being used. A standard PDF may include images, text, graphics, and formatting, but it may not be accessible to individuals with disabilities.

On the other hand, an accessible PDF, also known as a tagged PDF or a PDF/UA (Universal Accessibility) compliant PDF, is designed to ensure accessibility for people with disabilities, including visual impairments, hearing impairments, and mobility impairments. Accessible PDFs are created with specific features that allow assistive technologies, such as screen readers, to interpret and present the content to users in an accessible manner.

Here are some key differences between a standard PDF and an accessible PDF:

1. Structure and Navigation: Accessible PDFs have a logical structure and navigation features that allow users to navigate through the document using assistive technologies. This includes proper headings, paragraphs, reading order, lists, and tables that are tagged and labeled correctly.
2. Alternative Text: Images in an accessible PDF are accompanied by alternative text descriptions, allowing visually impaired users to understand the content of the images through assistive technologies.
3. Color and Contrast: Accessible PDFs ensure that color and contrast are used effectively, enabling users with visual impairments to read and comprehend the content. Important information conveyed through color alone is also provided through alternative means.
4. Text Accessibility: Accessible PDFs have selectable and searchable text, making it easier for users to locate and interact with the content using assistive technologies. The text is not part of an image or a scanned document.
5. Forms and Interactive Elements: Accessible PDFs include properly labeled form fields and interactive elements, such as checkboxes and radio buttons, that can be navigated and completed using assistive technologies.
6. Language Specification: Accessible PDFs specify the language used in the document, ensuring that screen readers and other assistive technologies pronounce the content correctly.

Creating an accessible PDF involves following specific guidelines and best practices, such as those outlined in the Web Content Accessibility Guidelines (WCAG) and the PDF/UA standard (ISO 14289) . By adhering to these guidelines, you can ensure that your PDF documents are accessible to a wider audience, including individuals with disabilities.

In summary, while a standard PDF focuses on preserving the visual appearance of a document, an accessible PDF goes a step further by incorporating features and structure that make the content perceivable and navigable for individuals with disabilities.