Checklist for Multilingual EPUB Accessibility Testing

Want to make your multilingual EPUBs accessible to everyone? Here's how to ensure your content is readable, navigable, and functional across languages and devices. Follow this checklist to meet accessibility standards like WCAG and EPUB Accessibility 1.1 and reach a global audience effectively.

Key Steps for Accessibility:

Language Settings: Use accurate language tags (lang and xml:lang) for correct pronunciation and display.
Text Display: Ensure fonts support all characters, text reflows smoothly, and text direction (dir attribute) is correctly applied for RTL languages.
Navigation: Test reading order, table of contents links, and heading structure for logical flow.
Media Elements: Add descriptive alt text for images, captions for videos, and transcripts for audio content.
Validation Tools: Use EPUBCheck and Ace by DAISY to confirm compliance with accessibility standards.

Why It Matters:

65% of users prefer content in their native language.
Multilingual accessibility can boost conversion rates by up to 20%.
Proper tagging and testing improve usability for screen readers and assistive technologies.

By following this checklist, you’ll create EPUBs that are inclusive, functional, and ready for a global audience. Dive into the details to make your content shine across languages and platforms.

EPUB Accessibility 101

Language Settings Check

To meet accessibility standards, it's crucial to declare accurate language settings in every EPUB file. These settings allow assistive technologies to handle multilingual EPUBs properly, ensuring they display and pronounce content as intended. This step is key to delivering smooth multilingual experiences across devices.

Language Tags and Codes

Correct language tagging plays a major role in making multilingual EPUBs accessible. Each EPUB file should include:

Setting Location	Required Attributes	Example
Root HTML Element	`lang` and `xml:lang`	`<html lang="en" xml:lang="en">`
Package Document	`xml:lang` on the package element	`<package xml:lang="en">`
Metadata Section	`dc:language` elements	`<dc:language>en-US</dc:language>`

When text includes multiple languages, wrap foreign phrases or sections in appropriate tags:

<p>The French phrase <span xml:lang="fr" lang="fr">bonjour le monde</span> means "hello world" in English.</p>

"Assistive technologies will read the text in the user's default language. This can lead to the entire text being mispronounced (when reading a publication in another language) or individual phrases being mangled (for inline foreign phrases)."

After tagging, ensure the language flow remains consistent across all platforms.

Language Flow Check

Use specialized tools to test and validate language flow:

Validation Tools
- Run EPUBCheck to confirm language code compliance
- Use DAISY ACE for accessibility checks
- Test with Thorium Reader's text-to-speech feature
Platform Testing
- Windows: epubjs + Firefox + NVDA
- MacOS: iBooks/Safari + VoiceOver
- Android: Chrome + TalkBack

Language Type	Code Example	Usage
Basic Language	`en`, `fr`, `de`	General language identification
Regional Variants	`en-US`, `fr-CA`	Location-specific variations
Script Variations	`zh-Hans`, `zh-Hant`	Writing system differences

If you're using BookTranslator.ai, double-check language tags to ensure accurate pronunciation during translations.

Text Display Check

Once language settings and flows are confirmed, it’s important to verify that the text displays correctly. Clear and consistent text presentation is key to making EPUB content accessible.

Font Support

The choice of fonts plays a critical role in displaying multilingual content effectively. Make sure the EPUB uses fonts capable of rendering different character sets accurately. Here’s a quick breakdown:

Font Type	Purpose	Example
Unicode-compatible	Supports basic multilingual text	Arial Unicode MS
Extended character sets	Handles special language features	Charis SIL
RTL script support	Displays Arabic or Hebrew text	Noto Sans Arabic

Check that fonts properly render special characters, diacritics, bold and italic styles, extended Unicode ranges, and any script-specific details.

Text Size and Flow

Ensure the text adjusts smoothly across various screen sizes and user settings. This includes:

Text reflowing correctly when users change font size, line spacing, margins, or orientation.
Images scaling clearly, wrapping properly, and adjusting their positions as needed.
Enlarged text maintaining clean layouts without overlaps, broken formatting, or navigation issues.

Text Direction

Set the text direction using the HTML dir attribute:

<html dir="rtl" lang="ar"> … <span dir="ltr">English text</span>

This ensures the base text direction is correctly applied, supports mixed-direction content, and aligns punctuation, numbers, and lists properly.

"Styles should be avoided for specifying direction, as the direction is the part of the text semantics and should be expressed in physical markup." - Sarmat89, Fanatic

Clear navigation is key for smooth access to content, especially for users relying on assistive technologies.

Reading Order

To ensure the reading order is correct, focus on two main areas:

Spine Order: Confirm that the spine follows the intended sequence.
Internal Document Flow: Check the flow within the document to match the spine's structure.

Example of proper document order:

<spine>
  <itemref idref="cover"/>
  <itemref idref="toc"/>
  <itemref idref="chapter1"/>
  <itemref idref="chapter2"/>
</spine>

For synchronized text-audio content, the text must align with both the spine and the internal flow.

Table of Contents Links

Test the Table of Contents (TOC) across various e-readers to ensure links work correctly and content displays as expected.

E-Reader	Testing Focus
Thorium Reader	Navigation and link functionality
Colibrio Vanilla	Language display and character rendering
Apple Books	Right-to-left (RTL) language support
Adobe Digital Editions	Compatibility across platforms

If the TOC order doesn’t match the spine, note this in the accessibility summary.

Heading Structure

Headings should follow a clear hierarchy, starting with a single <h1> for major sections and <h2> or <h3> for subsections. Keep the structure consistent across all languages.

Example:

<h1><span class="chapter-num">Chapter 1</span> Introduction</h1>

Key Guidelines:

Avoid using multiple heading tags for the same title.
Use <span> elements styled with CSS for decorative text.
Ensure the heading structure mirrors the TOC hierarchy.

For title pages, opt for styled <span> elements instead of extra heading tags. This approach maintains proper navigation while achieving the desired look.

These practices ensure a seamless reading experience across devices and languages.

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Media Elements Check

Make sure multimedia elements are accessible and functional in multiple languages.

Image Alt Text

Use descriptive, language-specific alt text for each image.

Steps to Test:

Confirm the presence of alt text.
Check for accurate translations.
Ensure the descriptions are culturally relevant.

Here's an example of multilingual alt text:

<img src="book-cover.jpg" 
     alt="A red leather-bound book with gold lettering"
     alt-fr="Un livre relié en cuir rouge avec des lettres dorées"
     alt-es="Un libro encuadernado en cuero rojo con letras doradas" />

Audio and Video Text

Provide text-based alternatives for all audio and video content.

What You’ll Need:

Audio: Complete transcripts and language markers.
Video: Captions that are timed correctly, audio descriptions, and transcripts.

Content Type	Accessibility Features Needed
Audio	Transcripts, language markers
Video	Captions, audio descriptions, transcripts
Interactive Media	Text alternatives, language-specific controls

Interactive Elements

Ensure forms, navigation controls, and error messages are translated correctly and work seamlessly in all languages.

Key Areas to Check:

Labels for form fields and their associations.
Navigation elements, including support for right-to-left (RTL) languages.
Error messages displayed in the appropriate language.

Both automated tools and manual testing with screen readers on various devices are essential to ensure thorough accessibility. These tests build on earlier checks, covering all content types for complete accessibility compliance.

Testing Tools Guide

Thorough testing is essential to ensure full multilingual EPUB accessibility. Here's how to approach it effectively, using both automated tools and manual methods.

Automated Tools

Ace, a widely-used free and open-source tool, checks EPUB conformance and provides detailed reports with visual insights.

"This is the tool which the industry needed to fully embrace the accessibility functionality which we've embedded into the EPUB 3 specification. We can now collectively move forward in producing content that enables the very best of reading experiences for all readers, reaching a higher audience as well as meeting our legal and moral obligations."
– George Kerscher, Chief Innovations Officer, The DAISY Consortium and Steering Committee W3C Publishing Business Group

Tool Name	Primary Function	Best For
Ace by DAISY	EPUB accessibility validation	Comprehensive accessibility check
EPUBCheck	EPUB specification conformance	Basic code validation
Accessibility Insights	Web-based accessibility testing	Browser-level accessibility

After running automated checks, follow up with manual testing to catch what tools might miss.

Manual Testing Steps

Manual reviews are key to identifying issues that automated tools may overlook. Focus on these areas:

Language Detection: Ensure proper language switching and correct pronunciation.
Navigation Flow: Check the document's structure and reading order.
Media Elements: Verify that all images and media have appropriate alternative texts and descriptions for each language.

These steps help refine accessibility further. To complement manual testing, use screen reader evaluations.

Testing with NVDA alongside Thorium Reader is highly recommended. Here’s how to configure and test:

Initial Setup
- Download Windows OneCore voices for all languages in your EPUB.
- Enable features like Speech Viewer (to monitor text output), Visual Highlight (to track focus), and Document Formatting (to ensure all elements are read).
Testing Process
- Navigate through the document systematically, checking for proper language voice switching, heading structure, image descriptions, and smooth navigation of lists and tables.
Verification Steps
- Confirm elements such as accurate language transitions, correct pronunciation of alternative texts, and clear navigation markers for tables and lists.

Combining automated tools with manual and screen reader testing ensures a thorough review. As Simon Collinson, Content Sales Manager at Kobo and Digital Producer at Tilted Axis Press, puts it: "The really important thing about Ace is that it makes accessibility a concrete target with clear steps and a hierarchy of severity."

Using BookTranslator.ai

BookTranslator.ai

BookTranslator.ai provides a translation solution designed to maintain accessibility features, ensuring translated EPUB files remain user-friendly for all audiences.

This tool simplifies the process of translating multilingual EPUBs while keeping critical accessibility elements intact.

Key Features

BookTranslator.ai safeguards important accessibility aspects during translation:

Feature	Accessibility Advantage
Smart Formatting	Keeps the original layout and styling, including text direction and font compatibility.
Language Tagging	Automatically retains correct language tags for screen readers.
Structure Retention	Preserves heading hierarchy and navigation for seamless usability.

The platform supports EPUB files up to 50MB, ensuring accessibility markers are preserved across its 99+ supported languages.

Accessibility Workflow

To ensure accessibility compliance during translation, follow these steps with BookTranslator.ai:

Pre-translation Check
Use Ace by DAISY to review the source EPUB file. This will provide a baseline accessibility score and highlight any existing issues.
Translation Configuration
Set up the translation with these steps:
- Turn on smart formatting to protect structural elements.
- Choose your target language from the 99+ available options.
- Confirm the file size is within the 50MB limit.
Post-translation Verification
After translation, run another check with Ace by DAISY to confirm accessibility features are intact. This ensures:
- Language tags are correctly applied.
- The document structure remains consistent.
- Alternative text is functional in the translated version.

For more complex publications requiring higher precision, consider BookTranslator.ai's Pro plan, priced at $9.99 per 100,000 words.

Final Steps

Main Points

Before you publish your multilingual EPUB, make sure these essential accessibility elements are in order. Use EPUBCheck and Ace by DAISY to verify them:

Component	What to Check
Language Settings	Ensure language tags are correctly applied to all content sections.
Document Structure	Confirm proper heading hierarchy and logical reading order.
Media Elements	Check that all images include alt text and media files have transcripts.
Navigation	Test the table of contents links and page navigation for proper functionality.

Complete Checklist

Here’s a step-by-step guide to finalize your EPUB and meet accessibility standards:

Run Technical Validation Use EPUBCheck to confirm your file meets EPUB specifications. This tool is commonly required by retailers and ensures your file is technically sound. Then, use Ace by DAISY for a deeper evaluation of accessibility.
Update Accessibility Metadata Add detailed accessibility information to your EPUB, such as:
- The version of the EPUB Accessibility specification used.
- WCAG version and conformance level (A, AA, or AAA).
- Credentials of the evaluator and the date of the assessment.
- A link to the public accessibility report.
Document Access Modes Clearly outline all access modes in your metadata, specifying:
- Primary text content.
- Any supplementary audio content.
- Visual elements.
- Interactive features.
Perform Final Testing Test your EPUB with various screen readers and assistive technologies. Focus on:
- Ensuring text and audio are synchronized with the logical reading order.
- Static page breaks that align with navigation needs.
- Usability of interactive elements.
- Font compatibility across all included languages.