Is PDF Accessible?
Adobe Systems introduced the Portable Document
Format (PDF) in 1993, and it has become widely used due to its ability to
preserve the exact appearance of printed material in digital form. The PDF/UA
(Universal Accessibility) standard, established in 2012, specifies
how to make PDFs accessible. This standard assures that PDFs can be read by
assistive devices, such as screen readers and text-to-speech programs, by
providing a logical arrangement of material via tags, regardless of visual
display.
Despite
these advancements, the format has significant accessibility issues. Regular
PDFs naturally lack flexibility; their set layout does not easily allow for
text reflow, font alteration, or other modifications that assistive
technologies exploit to better readability for visually impaired or
neurodiverse users. This can make navigating a document difficult for users
relying on screen readers, as these devices typically struggle to grasp the
structure or purpose of material without adequate tagging.
In
contrast, the EPUB format, which is gaining popularity in the eBook market,
includes more extensive accessibility capabilities. EPUB files are designed to
be dynamic and reflowable, adjusting text size, font, and color to match
individual user demands, and they contain support for extended descriptions and
other assistive technology.
The
transition towards EPUB does not render Accessible PDFs useless, however. PDFs
continue to be useful for certain types of content, particularly when perfect
layout duplication of print documents is required. They are still frequently
utilized in a variety of industries because to their ability to accurately
duplicate printed page layouts while also incorporating rich media and
annotations.
Given
the limits of PDFs, continual developments in accessibility standards and
technology are necessary. The introduction of more advanced labeling and
editing capabilities could enhance the usability of PDFs for accessibility
purposes. Nonetheless, as the eBook market matures, formats such as EPUB are
expected to dominate due to their inherent versatility and support for a
broader range of accessibility requirements.
Making a PDF accessible requires critical
procedures to ensure that the document can be utilized efficiently by persons
with impairments, particularly those who use assistive technologies such as
screen readers.
1.
Use Tags: Tags provide a hidden structured, logical order to the material in
the PDF, allowing assistive technologies to interpret the document's structure.
Tagging encompasses headings, paragraphs, lists, tables, and other content
elements. This helps screen readers browse the document and pronounce the
content appropriately.
2. Include Alternative Text: Images in PDFs
should have descriptions that screen readers can read. This text should explain
the image's purpose and content, rather than merely its appearance.
3.
Ensure Readable Text: Text in the PDF should be selectable rather than just an
image of text. This allows screen readers to read the content out loud. If the
PDF contains scanned images of text, Optical Character Recognition (OCR) needs
to be done to turn them into selectable text.
4.
Specify Document Language: Setting the document language in the PDF’s
properties helps assistive technologies like screen readers switch to the
appropriate language settings, ensuring correct pronunciation.
5.
Use a Logical Reading Order: In addition to labeling, the content should be
organized in a logical reading order. This implies that as the user navigates
the text with a keyboard or assistive device, the content is presented in a
logical order.
6.
Check Color Contrast: Make sure there is enough contrast between the text and
backdrop colors to help people with visual impairments.
7.
Create Simple and Consistent Layouts: Complex layouts might be confusing for
screen readers and difficult to navigate. Simplifying and consistent layouts
assist people predict where to find specific sorts of information.
8.
Include Bookmarks: In larger PDFs, bookmarks serve as a screen reader-friendly
table of contents, providing shortcuts to important areas of the text.
9.
Test with Screen Readers: Always test your PDFs with various screen readers
(such as JAWS, NVDA, or VoiceOver) to ensure that they are properly read and
that all contents are accessible.
10.
Use Accessibility Checkers: Tools like Adobe Acrobat Pro include built-in
accessibility checkers that will walk you through the process of discovering
and correcting accessibility issues in PDF documents.
Implementing these procedures ensures that PDFs
are not just compliant with accessibility standards like WCAG 2.0 and PDF/UA,
but also useable by a wider range of users.
Another way to make PDF Accessible is to use DPS. More here.