PDF/UA Compliance formally ISO 14289, is an International Organization for Standardization (ISO) standard for accessible PDF technology. Globally acknowledged as a compliance level, PDF/UA is a relatively consistent metric to compare against. WCAG (Web Content Accessibility Guidelines) is for websites and HTML-based material. PDF/UA (PDF Universal Accessibility) is the standard for document accessibility, particularly for PDF documents. The proper standard for PDFs is PDF/UA, as confirmed by the US Access Board. Though each standard was created by a separate nonprofit organization, they are both overseen and published by the International Organization for Standardization (ISO), a European-based organization. Make use of the WCAG standard for online pages. Use the PDF/UA standards when generating documents and PDFs. Despite their differences, all of these standards strive to provide universal access to digital material.

Understanding WCAG

WCAG, which is short for Web Content Accessibility Guidelines, is a set of guidelines that are necessary for improving web accessibility. The World Wide Web Consortium (W3C) developed these guidelines, which are the best method to ensure that your website is usable by everyone. They explain how to make digital services, websites, and apps accessible to everyone, The WCAG 2.0 and 2.1 provide a detailed set of guidelines for making web content more suitable for those with a broad range of disabilities. It is thorough but quite detailed, making it challenging to quickly understand.

Understanding the Four Principles of Accessibility

The four main principles of WCAG are requirements that must be met by web content in order for it to be considered accessible:

  • Perceivable: It must be capable of being perceived by users through one or more senses.
  • Operable: Is the web content able to be navigated, data entered, or otherwise interacted with by a user?
  • Robust: Information needs to be sufficiently resilient to be consistently understood by a range of user agents, including assistive devices.
  • Comprehensible: Information and user interface features should be understandable.

WCAG Levels: A, AA, AAA

The guidelines are divided into three compliance levels to give an ordered structure:

Level A 

Level A success criteria are the easiest to achieve and have minimal bearing on the structure or design of the website.

Level AA 

Level AA takes the accessibility of web material to a new level by allowing users to view it in more situations.

Level AAA

The most comprehensive standard for digital accessibility, WCAG AAA, is the benchmark to aim toward.

Understanding PDF/UA

The goal of the PDF/UA standard, formerly known as ISO 14289-1, is to guarantee that PDFs are accessible to all users. It establishes minimal standards to ensure that documents are compatible with devices that assist those with disabilities, and it is directed at all parties engaged in the creation of PDFs…

Key Components of PDF/UA

Alternative Text: To ensure that those who are blind or visually impaired understand the meaning of images and other non-textual elements, alternative text descriptions should be included. 

Color Contrast: PDF/UA guidelines address color contrast to ensure that text and other elements are distinguishable by users with visual impairments.

Tagged PDF: Ensures the document structure is understandable by assistive technologies.

Difference between a PDF and an accessible PDF

Regarding WCAG: The Web Accessibility Initiative (WAI), a division of the World Wide Web Consortium (W3C). The ISO has approved and released the WCAG as ISO/IEC 40500:2012. WCAG compliance and offers methods for certain platforms including HTML, CSS, Flash, and PDF.

The PDF Association: (PDFA) created and wrote the PDF/UA standard, which ISO ratified and published as ISO 14289-1. PDF/UA for scripting to enable the accessibility of embedded multimedia material and other similar content types in PDF.

Case Studies 

WCAG Implementation Examples 

Several organizations have successfully implemented WCAG standards, resulting in more accessible websites. For instance, a university redesigned its website to meet WCAG 2.1 AA standards, significantly improving accessibility for students with disabilities.

Tools for PDF Compliance

Popular Tools: 

Tools for WCAG Compliance

Popular Tools: 

  • Dynomapper
  • WAVE
  • Axe
  • Lighthouse 

Challenges in Implementing WCAG

  • Cross-Browser and Platform Compatibility: Achieving consistent WCAG compliance across different platforms and screen sizes presents a significant challenge. To guarantee accessibility across a range of platforms and devices, developers must use responsive design strategies and conduct comprehensive testing of their programs on diverse configurations.
  • Low contrast text: The most commonly detected accessibility issue was low contrast text. According to WCAG 2, contrast is the difference of brightness between two colors, and text with color contrast that’s below the WCAG 2 AA thresholds was found on 83.6% of home pages.
  • Missing or Inaccurate Text Alternatives for Images A key step in improving website accessibility is ensuring that all images include descriptive text alternatives. For those who use screen readers, these alternatives—also referred to as alt text—are essential for understanding visual material.

Challenges in Implementing PDF/UA

  • Headings: Headings are there but they are not necessarily tagged as such! Most PDFs floating on the web make use of different presentation techniques for adding headings and sub-headings in a document but they are not tagged as headings.
  • Tagging: The Correct Content Our role as remediators is to tag the content on the page so that a reader using assistive technology can access the same content as a sighted reader.
  • Table Usage & Formatting: Tables can be an incredible way of displaying information while showing relationships between specific data sets. Scientific reports, for example, rely on data tables to articulate data-supported concepts.

Different formats suit different types of content and different people (in some cases, Microsoft Word will work better than either HTML or PDF). There is no one-size-fits-all solution. The format is not the “problem” with inaccessible PDFs. It’s the widespread lack of knowledge as to how to author them properly.


Digital accessibility is a vital aspect of modern content creation. Both WCAG and PDF/UA play crucial roles in ensuring that web content and PDF documents are accessible to all users. Understanding the differences and similarities between these standards helps organizations make informed decisions about compliance and inclusivity.

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