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Creating Accessible Files

Creating Accessible Files

This section includes resources that may be helpful as you assess and remediate files in your repository. However, you should consult with accessibility offices on your campus to determine appropriate tools.

Accessible PDFs

Resources for creating and verifying accessible PDFs:

PDF Accessibility Checks: Good, Better, Best

The following are suggestions for how to prioritize accessibility checks for PDFs in your repository.

GOOD: Minimum acceptable accessibility for PDFs

The items below align with WCAG 2.0 / 2.1 Level A/AA and address the most common access barriers. If you have limited resources, you should do these things first.

The checks below can be partially automated using Acrobat Pro’s Accessibility Checker, but manual review is required to ensure that tags, reading order, headings, and alt text are meaningful and accurate.

Tag PDFs

  • Add tags so that assistive technologies can understand the structure and reading order of the document. Untagged PDFs are largely unusable to assistive technology users.

  • Why this matters (WCAG 2.1AA): WCAG 1.3.1 (Info and Relationships) requires that document structure be programmatically determinable.

  • How to add or fix tags in Acrobat Pro:

  • Open the PDF in Acrobat Pro

  • Go to Tools → Accessibility → Autotag Document (if the document is untagged)

  • Open the Tags panel (View → Show/Hide → Navigation Panes → Tags)

  • Review and adjust tag structure as needed using the Reading Order tool

Create a Descriptive Document Title

  • The document title appears in the window title bar and is announced to users by screen readers. Filenames are often cryptic and do not provide meaningful context to a user about what the document is.

  • Why this matters (WCAG 2.1AA): WCAG 2.4.2 (Page Titled) requires a descriptive title for each page or document.

  • How to do in Acrobat Pro:

    • Go to File → Properties → Description tab

      • Enter a meaningful Title (not just the filename)

    • Go to Initial View tab → Window Options

      • Set Show: Document Title

Set Primary Language

  • The document language tells screen readers which pronunciation rules to use. Without this, content may be read incorrectly, especially for non-English documents.

  • Why this matters (WCAG 2.1AA): WCAG 3.1.1 (Language of Page) requires the primary language of content to be programmatically identified.

  • How to fix / check in Acrobat Pro:

    • Go to File → Properties → Advanced tab

    • Under Reading Options, set the Language (e.g., English)

Add Alternative Text for Images and Tables

  • Alternative text (alt text) provides a text description of non-text content such as images, charts, and diagrams. Decorative images should be marked as artifacts so screen readers skip them.

  • Why this matters (WCAG 2.1AA): WCAG 1.1.1 (Non-text Content) requires text alternatives for meaningful visual content.

  • How to fix / check in Acrobat Pro:

    • Go to Tools → Accessibility → Set Alternate Text (guided workflow), or

    • Use Reading Order tool:

      • Right-click an image → Edit Alt Text

      • Provide a concise, meaningful description

      • Mark decorative images as Background/Artifact

Tables with Headers and Logical Structure

  • Accessible tables use header cells (TH) and data cells (TD) so screen readers can announce row/column relationships.

  • Why this matters (WCAG 2.1AA): WCAG 1.3.1 (Info and Relationships) requires that document structure be programmatically determinable.

  • How to fix / check in Acrobat Pro:

    • Open Reading Order tool

    • Select the table and ensure it is recognized as a table

    • Open the Table Editor

      • Set header cells

      • Confirm rows and columns are properly structured

Lists Use Proper List Structure

  • Lists must be real list elements (not just hyphens or numbers typed manually). Screen readers use list tags to announce list length and structure.

  • Why this matters (WCAG 2.1AA): WCAG 1.3.1 (Info and Relationships) requires semantic list structure.

  • How to fix / check in Acrobat Pro:

    • Open the Tags panel

    • Verify that lists use L, LI, and LBody tags

    • Use Reading Order tool to retag incorrectly formatted lists

Headings Use a Logical Hierarchy

  • Headings provide navigational structure. Skipping levels (e.g., H1 → H3) or using headings only for visual formatting breaks logical navigation.

  • Why this matters (WCAG 2.1AA): WCAG 2.4.6 (Headings and Labels) requires meaningful, descriptive structure. 

  • How to fix / check in Acrobat Pro:

    • Open Tags panel

    • Ensure headings follow a logical order (H1 → H2 → H3)

    • Use Reading Order tool to change paragraph tags to heading tags where appropriate

Sufficient Color Contrast

  • Text and essential visual information must have enough contrast with the background to be readable by users with low vision or color vision deficiencies.

  • Why this matters (WCAG 2.1AA): WCAG 1.4.3 (Contrast – Minimum) requires sufficient contrast for normal text and large text.

  • How to fix / check in Acrobat Pro:

    • Acrobat Pro does NOT reliably check color contrast.

    • Because of this, users must perform this step manually.

    • Consult with your institution about available tools for checking color contrastww

BETTER: Complete WCAG 2.1 Conformance for PDFs

These practices go beyond baseline compliance and significantly improve usability for screen reader users, keyboard-only users, and people using magnification or alternative input devices. These are strongly recommended for high-use or instructional materials but may require more resources to perform.

Like in the GOOD section, the checks below can be partially automated using Acrobat Pro’s Accessibility Checker, but manual review is required to ensure that tags, reading order, headings, and alt text are meaningful and accurate.

Tab Order Matches Reading Order

  • The order in which content receives keyboard focus (Tab key) should follow the same logical reading order as the document structure. If tab order is wrong, keyboard and screen reader users may experience content in a confusing sequence.

  • Why this matters (WCAG 2.1AA): WCAG 2.4.3 (Focus Order) requires that focus moves through content in a logical, meaningful order.

  • How to fix / check in Acrobat Pro:

    • Go to Tools → Accessibility → Reading Order

    • Select Show Tab Order

    • Use the Order panel (View → Show/Hide → Navigation Panes → Order)

    • Drag items to match the correct reading sequence

    • Test by pressing Tab repeatedly in the document

No Image-Only PDFs (OCR When Needed)

  • Text in PDFs must be actual, selectable text and can not just be “images” of text. Scanned PDFs without OCR cannot be read by screen readers or searched and are thus less accessible.

  • Why this matters (WCAG 2.1AA): WCAG 1.1.1 (Non-text Content) and WCAG 1.4.5 (Images of Text) discourage images of text when real text can be used.

  • How to fix / check in Acrobat Pro:

    • Try selecting text with your cursor

    • If text cannot be selected, the PDF is image-only

    • Go to Tools → Scan & OCR → Recognize Text → In This File

    • Review and correct OCR errors manually

Tag All Content or Mark as Artifact

  • Every piece of content in a PDF must either be part of the tag tree (so assistive technologies can access it) or explicitly marked as an artifact (decorative content that should be ignored).

  • Why this matters (WCAG 2.1AA): WCAG 1.3.1 (Info and Relationships) requires that all meaningful content be programmatically determinable.

  • How to check/fix in Acrobat Pro:

    • Open the Tags panel

    • Use Accessibility Checker to identify untagged content

    • Use the Reading Order tool to tag content correctly

    • Mark decorative elements as Background/Artifact

Tag Annotations

  • Comments, highlights, and editorial marks should be available to screen reader users when they convey meaning. Decorative annotations should be marked as artifacts.

  • Why this matters (WCAG 2.1AA): WCAG 1.3.1 (Info and Relationships) requires meaningful content to be programmatically available to assistive technologies.

  • How to check/fix in Acrobat Pro:

    • Open the Tags panel

    • Locate annotations in the tag tree

    • Ensure meaningful annotations are properly tagged

    • Mark purely decorative annotations as artifacts

BEST: WCAG 2.2+, PDF/UA, and Future Proofing

These practices represent the highest level of PDF accessibility. They go beyond baseline legal compliance and focus on long-term usability, interoperability with assistive technologies, and archival-quality accessibility. BEST-level remediation is recommended for theses, dissertations, high-use publications, and materials intended for long-term preservation.

PDF/UA Conformance

  • PDF/UA (ISO 14289) is the international standard for universally accessible PDFs. It defines strict requirements for tagging, structure, metadata, and text encoding to ensure consistent accessibility across assistive technologies and platforms.

  • Why this matters (WCAG 2.2+ & PDF/UA): PDF/UA operationalizes WCAG principles in the PDF format and supports WCAG 4.1.2 (Name, Role, Value) and 1.3.1 (Info and Relationships) by enforcing robust, machine-readable structure.

  • Why this is not WCAG 2.1AA: WCAG 2.1 is format-agnostic and does not require conformance to PDF/UA. PDF/UA includes additional technical constraints (e.g., tag role mapping, structure tree completeness) that exceed WCAG’s baseline requirements.

  • How to check/fix in Acrobat Pro:

    • Run Accessibility Checker (Tools → Accessibility → Accessibility Check)

    • Manually inspect the Tags panel for complete and logical structure

    • Address issues such as missing tags, incorrect roles, and untagged content

    • Validate using an external PDF/UA checker (Acrobat provides partial coverage)

Add Bookmarks to Long Documents

  • Bookmarks provide an outline-based navigation structure that mirrors document headings. They are especially important for long PDFs (e.g., 20+ pages).

  • Why this matters (WCAG 2.2+ & usability): Supports efficient navigation and orientation for screen reader and keyboard users and aligns with WCAG 2.4.5 (Multiple Ways) and 2.4.6 (Headings and Labels) as a usability enhancement.

  • Why this is not WCAG 2.1AA: WCAG 2.1 AA does not require bookmarks in PDFs. Navigation can technically meet WCAG using headings alone, so bookmarks are considered an enhancement rather than a compliance requirement.

  • How to check/fix in Acrobat Pro:

    • Open the Bookmarks panel

    • Use New Bookmark or Create Bookmarks from Structure

    • Ensure bookmarks mirror heading hierarchy and section structure

    • Avoid overly generic bookmark labels (e.g., “Section 1”)

Character Encoding Is Clean

  • Proper character encoding ensures text is programmatically determinable and correctly interpreted by assistive technologies.

  • Why this matters: Encoding problems can cause screen readers to mispronounce or skip content, especially for symbols, formulas, or non-Latin characters.

  • Why this is not WCAG 2.1AA: WCAG 2.1 focuses on user-facing outcomes and does not prescribe low-level encoding constraints. Some encoding failures affect usability but may not trigger a specific WCAG 2.1 AA failure in automated checks.

  • How to check/fix in Acrobat Pro:

    • Copy/paste text to verify integrity

    • Test with a screen reader

    • Fix encoding in the source document and re-export

No Nested Alternate Text Errors

  • Alternate text must be attached directly to the element it describes. Nested or container-level alt text can be skipped by screen readers.

  • Why this matters: Misplaced alt text can result in important descriptions never being announced to users.

  • Why this is not WCAG 2.1AA: WCAG 2.1 AA requires that non-text content have text alternatives, but it does not specify PDF tag placement rules. Nested alt text errors are specific to PDF/UA’s stricter technical model and how screen readers parse PDF structure.

  • How to check/fix in Acrobat Pro:

    • Review Figure tags in the Tags panel

    • Move alt text to the correct object

    • Avoid applying alt text to container tags

Table Regularity

  • Tables use consistent row and column structures without irregular or visually merged cells that lack proper tag representation.

  • Why this matters: Regular tables are more reliably navigable by screen readers and less likely to break header vs. data relationships.

  • Why this is not WCAG 2.1AA: WCAG 2.1 requires that relationships be programmatically determinable but does not require tables to follow a regular grid pattern. Table regularity is a PDF/UA quality requirement that improves robustness but exceeds WCAG’s baseline.

  • How to check/fix in Acrobat Pro:

    • Inspect table tags using the Table Editor

    • Simplify complex tables in the source document

    • Re-export when Acrobat cannot reliably repair structure

Other WCAG 2.2+ Enhancements (Where Applicable)

  • WCAG 2.2 introduces improvements related to focus visibility, target size, and interaction predictability, which are most relevant for interactive PDFs (forms, linked reports).

  • Why this matters: These enhancements improve usability for users with motor, cognitive, and low-vision disabilities and help future-proof documents.

  • Why this is not WCAG 2.1AA: WCAG 2.2 criteria were not part of WCAG 2.1 AA and therefore are not required for 2.1-based compliance targets. Applying them represents an accessibility best practice beyond the baseline.

  • How to check/fix in Acrobat Pro:

    • Test keyboard navigation and focus indicators

    • Check clickable target size in interactive PDFs

    • Fix interaction issues in the source authoring tool

Accessible Audio and Video Items

  • Include closed captioning files with any video and a downloadable transcript file for any audio.

The DSpace embedded Media Player supports Web VTT captioning. You must upload the Web VTT file as a separate file from the video (i.e. DSpace does not generate a Web VTT file on its own.

See TDL’s DSpace documentation for more information about how to include Web VTT caption files.

  • Include a transcript of the video or audio file. A transcript should include not only what is spoken in the video, but also descriptions of important visual information. If you have already created a caption file, you can edit or add to the text of the caption file to create a transcript.

    • Upload a transcript as a separate file as part of the DSpace item and label it clearly.

  • Include audio descriptions that are spoken narratives of the visual content in a video. This can be accomplished in a number of ways:

    • When the video is created, speakers can describe any important visual content (graphs, charts, etc.).

    • Audio description may need to be added to a video after-the-fact, which requires recording new audio and editing it into the original video. 

    • The University of South Carolina website includes helpful information about adding audio description.

Examples: