PDF/A – The format of the future – Part 4: PDF/UA

Accessibility stamp

After parts 1 to 3 of this series covered PDF/A-1, PDF/A-2, and PDF/A-3, this part focuses on PDF/UA and the creation of accessible PDF documents.

Since 2012, PDF/UA has been established as the ISO standard 14289-1 for creating accessible PDF documents. In this context, "UA" stands for "Universal Accessibility."

What is accessibility?​

The core idea of accessibility is to ensure that all people can access information and communication without unnecessary barriers. This means reducing existing barriers as much as possible. A typical barrier is when people cannot access information due to visual impairment or another disability. The same applies to PDF documents that cannot be opened, read, or interpreted by assistive technologies. Websites can also be inaccessible when people are limited by age, social background, or outdated technology.

Today, many technologies help people with disabilities use computers and access digital content. These include screen readers, eye-tracking controls, mouth-operated input devices, and refreshable braille displays.

Accessibility: legally relevant since 2012​

PDF/UA plays a key role in supporting accessible information. Accessible PDFs are especially important for public institutions, where accessible information technology is legally required. Since 2002, German law (Section 11 of the Equal Rights for Persons with Disabilities Act) has required federal authority websites to be accessible. In the private sector, accessible information is strongly recommended as well. That means websites and PDFs should be designed to be accessible wherever possible. For modern businesses, this is also a signal of professionalism and social responsibility, while helping reach a broader audience.

How does a classic PDF differ from PDF/UA?​

Traditional PDFs mainly aim to preserve the original visual appearance. Accessibility, however, also requires adaptable presentation and interaction. This includes font style and size, color rendering, keyboard usage, reading order, and compatibility with speech technologies.

PDF/UA was developed to meet these requirements and has been an ISO standard since 2012. Besides inclusion and broader reach, PDF/UA documents provide practical benefits for mobile usage on tablets and smartphones. In addition, accessible websites and PDF documents improve overall usability. Search engines also reward user-friendly, well-structured, and reliable content.

Bottom line: accessible PDF documents should provide equal quality and readability for everyone.

Key requirements for accessible PDFs​

  • Tags to structure the document in a logical reading order
  • Defined document language
  • Clear document structure and logical reading sequence
  • Consistent headings and style templates
  • Navigation aids such as links, table of contents, and bookmarks
  • Alternative text for images, graphics, links, and form fields
  • Images placed inline with text when possible
  • Sufficient text contrast and spacing
  • Security settings that do not block screen reader usage
  • Correctly structured and tagged tables
  • Accessible form fields
  • Adjustable font size

How do you create a document in PDF/UA format?​

Before generating a PDF, use proper styles, headings, and paragraphs in your word processor. Every image should have alternative text, and hyperlinks should be defined correctly in the source document. This reduces effort later during PDF/UA conversion. A practical approach is to prepare accessibility in advance (for example in Microsoft Word), then run the built-in accessibility checker before converting to PDF/UA.

Accessibility check in Word

After conversion, the PDF can be tested and optimized in most PDF readers. Well-structured source documents are essential because they usually lead to a clear and consistent reading order.

Creating accessible PDFs does require additional work, for example adding tags and bookmarks. However, this effort has clear value: well-structured and well-formatted content is easier for everyone to read, not only for users who rely on accessibility features.

Check PDFs for accessibility​

Proper testing and validation of accessibility are highly recommended. A useful guide can be found here: Checklist: Accessible PDF documents.

Additional tips for checking PDF/UA​

  1. You can test accessibility in Microsoft Word via File -> Info -> Check for Issues -> Check Accessibility.
  2. To check whether an existing PDF is tagged, open it in Adobe Acrobat Reader and go to File -> Properties -> Description (Ctrl+D). The field Tagged PDF should show Yes.
  3. To generate tagged PDFs, use Save & Send rather than printing to PDF.
  4. Define a document title and primary language at the beginning.

Other PDF formats​

  • PDF/X (graphics and printing)
  • PDF/E (engineering documents)
  • PDF/H (healthcare documents)
  • PDF/VT (high-volume variable and transactional printing)