Why document format matters for accessibility

Universities and public sector organisations publish thousands of documents each year — course handbooks, assessment briefs, policy documents, lecture materials, and administrative forms. The format in which these documents are published has a direct and measurable impact on whether they are accessible to people with disabilities.

Despite growing awareness of digital accessibility obligations, pdf remains the default publishing format across much of higher education. This default is largely inherited rather than evidence-based. Research consistently shows that structured, editable formats such as html and docx are easier to make accessible, more compatible with assistive technologies, and significantly less costly to maintain at scale.

This post draws on large-scale user research from WebAIM's Screen Reader User Surveys (2019–2024), industry data from Adobe and the National Federation of the Blind, practitioner guidance from organisations including RNIB, AbilityNet, and the UK Government Digital Service, and expert commentary from accessibility specialists working in higher education. The evidence points in a consistent direction — and the implications for institutional document strategy are clear.

The core finding

Screen reader users overwhelmingly prefer Word over pdf. The evidence is clear and consistent across multiple surveys spanning five years.

That is a greater than 5:1 preference for Word over pdf among people who rely on screen readers to access documents every day.

Recommended format hierarchy

Accessibility practitioners and international publishing guidance consistently recommend the same priority order for document formats.

"The gold standard for web content is html. It is OK to publish alternate versions of web content in Word or pdf, but if only one version is to be published, it should be in html. Word is preferable to pdf."

— University of Melbourne, Accessibility Guidance

The pdf accessibility problem

WebAIM Survey #8 (2019) asked screen reader users which document formats were likely to cause accessibility problems. The results show a stark gap.

Scale of pdf inaccessibility

Industry data paints a consistent picture: the vast majority of pdf documents in circulation are not accessible.

Mobile accessibility matters

Document format choices must account for the reality that the vast majority of assistive technology users now access content on mobile devices, where fixed-layout pdfs are particularly problematic.

Structured formats such as html and docx reflow naturally on mobile screens. Pdf documents maintain fixed layouts that often require horizontal scrolling, pinch-to-zoom, or render in ways that break assistive technology navigation on smaller screens.

Why pdf reflow fails in practice

Reflow in pdf is only available when documents are opened in Adobe Reader. It does not function when pdfs are opened in browsers or in Adobe Digital Editions, which limits its usefulness in web-based VLE contexts where users typically access content. Even in Adobe Reader, reflow failures are common: content may refuse to reflow entirely, pages containing images may not reflow while other pages do, page content may become hidden beneath page breaks resulting in missing or misinterpreted information, and word spacing may collapse so that adjacent words merge together, significantly affecting readability at 300% or 400% magnification.

Virtual learning environments and content delivery

VLEs such as Moodle, Brightspace, Canvas, and Blackboard render html content natively. Documents uploaded as pdfs bypass VLE accessibility features such as built-in text-to-speech, immersive readers, and responsive display. Content created directly within the VLE as html or uploaded as docx integrates with these tools automatically.

Tools such as Microsoft Immersive Reader support reading comprehension, personalisation, and simplified presentation, particularly valuable for users with dyslexia, ADHD, or other cognitive and learning differences. These tools work best with structured document formats.

The cost of retrospective pdf remediation

Remediating inaccessible pdfs after the fact is expensive and time-consuming. Creating accessible source documents from the start is significantly more efficient.

"Remediating a pdf file created from an inaccessible Word file takes much more time than creating an accessible Word file and then exporting it as a pdf."

— University of Colorado, Digital Accessibility Office

When pdf remains appropriate

High-quality, born-accessible pdfs remain valuable in specific contexts. The argument is not that pdf should never be used, but that it should not be the default when more accessible alternatives exist.

• Exact layout fidelity is required (e.g. examination papers, official transcripts)
• Digital signatures are needed (e.g. contracts, award parchments)
• Documents must remain final and uneditable (e.g. published policies, regulations)
• Long-term archival is required using pdf/a (e.g. research theses, institutional records)
• Specialist accessible pdf production workflows are in place

Best practice recommends offering accessible html or docx alternatives alongside pdf where possible, even when pdf is the primary distribution format.

Format comparison at a glance

Recommended format by use case

Regulatory context for Irish public bodies

Regulatory enforcement has repeatedly identified downloadable documents, particularly pdfs, as a major accessibility risk area. Together, the European Accessibility Act, Public Sector Bodies Regulations, Disability Act, and Equal Status Acts create strong compliance incentives to prioritise accessibility at the content creation stage rather than relying on reactive remediation.

Implementation recommendations

Public sector and higher education organisations should consider the following actions to strengthen document accessibility compliance and reduce operational risk.

1. Adopt structured authoring as the default. Create new documents in html or docx using built-in accessibility features. Avoid creating content directly in pdf unless specialist workflows are in place.
2. Audit existing pdf document estates. Prioritise high-traffic, public-facing content. Identify documents lacking accessibility tagging or alternatives.
3. Train content teams. Provide practical training in accessible authoring — heading structures, alt text, table accessibility, use of built-in accessibility checkers, and correct export to pdf. Integrate this into staff induction and professional development.
4. Embed accessibility in VLE and content guidelines. Encourage html content creation within VLEs and docx uploads over pdf. Templates and exemplars should model accessible practice.
5. Include accessibility in procurement. Require that externally produced documents meet accessibility standards. Contracts should specify acceptance criteria referencing WCAG and, where applicable, pdf/ua conformance.
6. Establish governance. Assign responsibility for document accessibility, maintain accessibility statements, and track remediation progress. A named accessibility lead should oversee institutional progress.
7. Provide accessible alternatives. Where immediate remediation is not feasible, publish a clear process for users to request alternative formats, as required under the Disability Act 2005 and Public Sector Bodies Accessibility Regulations.