Accessible EPUB Backlist Remediation: A Publisher’s Guide to Scaling Legacy Titles

Accessible EPUB Backlist Remediation: How Publishers Can Fix Legacy Titles at Scale

For many publishers, accessibility is no longer primarily a frontlist problem.

The difficult question is what to do with hundreds, thousands or tens of thousands of older ebooks already sitting in the catalogue.

Legacy EPUBs may contain:

• Weak or missing semantic structure
• Missing image descriptions
• Poor heading hierarchy
• Incomplete navigation
• Inaccessible tables
• Missing language information
• EPUB 2-era markup
• Missing accessibility metadata
• Validation errors
• Content that has never been tested with assistive technology

Since 28 June 2025, the European Accessibility Act has been in application across the EU, covering key products and services including ebooks.

The publishing response is visible in the market. Bloomsbury states that its new EPUB editions follow EPUB Accessibility 1.1 and WCAG 2.2 AA and that it is remediating an extensive backlist where older files do not meet its accessibility standards.

For publishers, the challenge has therefore shifted from:

“How do we make one EPUB accessible?”

to:

“How do we make an entire catalogue accessible without losing control of quality, metadata, schedules and cost?”

Quick Answer: What Is EPUB Backlist Remediation?

EPUB backlist remediation is the process of auditing and correcting existing ebook files so that older titles provide more accessible structure, navigation, descriptions and metadata.

A scalable programme usually follows:

Inventory → Audit → Classify → Prioritize → Remediate → Validate → Human QA → Metadata → Deliver

The mistake is treating a 20,000-title catalogue as 20,000 identical conversion jobs.

Backlists vary enormously.

A text-led monograph may require relatively straightforward structural remediation.

A heavily illustrated textbook containing charts, tables, equations and complex navigation may require substantially more human review.

Why Legacy EPUBs Become an Accessibility Risk

Older ebooks were often created for a different publishing environment.

A file may still open correctly in a reading system while containing accessibility problems underneath.

Typical examples include:

• Headings styled visually instead of semantically
• Images without useful alternatives
• Generic link text
• Weak navigation
• Tables without meaningful structure
• Missing page navigation
• Incorrect document language
• Poor reading order
• Legacy markup
• Missing accessibility metadata

This distinction matters:

A valid EPUB is not automatically an accessible EPUB.

EPUB validation and accessibility evaluation answer different questions.

EPUB 2 to EPUB 3: Conversion Alone Is Not Enough

One common backlist strategy is EPUB 2 → EPUB 3 migration.

That can be useful.

But changing the package format alone does not magically repair accessibility.

A legacy title converted to EPUB 3 may still contain:

• Poor semantics
• Missing alt text
• Incorrect heading hierarchy
• Weak table markup
• Missing accessibility metadata
• Navigation problems

The real workflow should therefore be:

Legacy EPUB

↓

Structural Assessment

↓

EPUB 3 Conversion

↓

Accessibility Remediation

↓

Validation + Human QA

↓

Accessible Distribution File

The distinction is important when comparing vendors.

Ask whether the supplier is quoting for format conversion or genuine accessibility remediation.

What Should Be Audited in an EPUB Backlist?

A useful audit examines several layers.

1. Semantic Structure

Review:

• Headings
• Paragraphs
• Lists
• Block quotes
• Figures
• Captions
• Notes
• Tables

The structure should communicate the purpose of content rather than simply reproduce visual styling.

2. Navigation

Check whether users can efficiently move through the publication using:

• Table of contents
• Heading navigation
• Landmarks
• Page navigation where applicable
• Internal links

Navigation becomes particularly important in textbooks, reference works and long academic publications.

3. Images and Alternative Text

Determine whether each meaningful visual has an appropriate text alternative.

Do not evaluate alt text simply by asking:

“Is something present in the alt attribute?”

Instead ask:

“Does the description communicate what the reader needs from this image?”

Complex content may require different treatment for:

• Charts
• Diagrams
• Maps
• Scientific illustrations
• Infographics
• Equations

Human judgment remains important here.

4. Tables

Tables should be reviewed for:

• Header structure
• Relationships between cells
• Captions
• Reading sequence
• Complex or nested structures

Visual appearance alone cannot establish whether a table is understandable through assistive technology.

5. Language

The publication and relevant language changes should be identified correctly.

This can affect pronunciation and interpretation by assistive technologies.

6. Accessibility Metadata

Accessibility cannot help readers make informed choices if it is invisible at the discovery layer.

World Wide Web Consortium's EPUB Accessibility 1.1 specification includes accessibility metadata requirements specifically to support the discoverability of an EPUB publication's accessibility characteristics.

That makes metadata part of the accessibility workflow—not an optional marketing field added afterwards.

How Should Publishers Prioritize a Large Backlist?

Attempting to remediate every title simultaneously can make the programme unnecessarily difficult.

A more practical model uses prioritization.

Other useful prioritization factors include:

• Sales activity
• Territory
• Distribution channel
• Customer requests
• Institutional adoption
• Complexity
• Source-file availability
• Legal/commercial exposure

Key Point

Prioritize by risk, demand and complexity—not alphabetically by ISBN.

Why Representative Sampling Matters

Before quoting or scheduling a large backlist programme, select a representative sample.

Include examples of:

• Simple reflowable EPUBs
• Older EPUB 2 files
• Image-heavy titles
• Tables
• Footnotes/endnotes
• STEM content
• Multi-language publications
• Fixed-layout titles
• Titles with poor source files

Sampling helps reveal recurring defects before full production begins.

It also allows the publisher and remediation partner to establish:

• Complexity categories
• Remediation rules
• QA expectations
• Exceptions
• Estimated throughput

Automated Accessibility Checking vs Human QA

Automated tools are valuable for finding repeatable technical problems.

But they cannot make every editorial accessibility decision.

The current market itself increasingly acknowledges this distinction. Origami, for example, describes automated repair for mechanical accessibility issues while flagging areas requiring human judgment.

The stronger model is:

Automated Audit + Human Remediation + Assistive-Technology QA

Accessibility Metadata Must Travel With the EPUB

One of the most overlooked backlist problems is metadata.

An accessible EPUB should communicate relevant accessibility characteristics so that distributors and readers can understand what the publication supports.

EPUB Accessibility 1.1 specifically addresses accessibility metadata and discoverability.

Useful metadata can describe areas such as:

• Access modes
• Sufficient access modes
• Accessibility features
• Accessibility hazards
• Accessibility summary
• Conformance information

Internal EPUB metadata and external distribution metadata should also be kept consistent.

This is particularly important when accessibility information moves through:

Publisher → Distributor → Retailer → Library → Reader

Common Backlist Remediation Mistakes

Converting every EPUB 2 file automatically

Format migration does not guarantee accessibility.

Running a checker and treating “pass” as completion

Automated tools cannot assess every contextual issue.

Generating all alt text without editorial QA

Description quality depends on purpose and context.

Ignoring metadata

An accessible publication that cannot communicate its accessibility characteristics creates a discoverability problem.

Using one complexity assumption for every title

A novel and a STEM textbook should not be scoped identically.

Skipping retesting

Corrections can introduce new structural or navigation problems.

Questions to Ask an EPUB Remediation Partner

Before outsourcing a backlist, ask:

• How do you audit the catalogue before production?
• How do you classify complexity?
• Can you handle EPUB 2 → EPUB 3 migration?
• How are alt-text decisions reviewed?
• How are tables and complex content handled?
• Which accessibility validation tools are used?
• Is human assistive-technology testing included?
• How is accessibility metadata created and validated?
• Can existing ONIX workflows be supported?
• How are failed titles corrected and retested?
• What QA evidence accompanies delivery?
• How is consistency maintained across thousands of titles?

A supplier should be able to describe the workflow, not simply claim that its output is accessible.

How Gentize Supports Accessible Backlist Production

Gentize's published Accessibility practice currently includes:

• PDF/UA and accessible EPUB remediation
• WCAG 2.2 AA auditing and remediation
• NVDA, JAWS and VoiceOver testing
• Alt-text and structural tagging
• EPUB and ONIX accessibility metadata
• Accessibility documentation

Gentize also publicly states that its accessibility production is backed by 50+ A11Y-certified testers with visual impairments.

Most relevant to this topic, Gentize publishes a case study for a 35,000-title backlist accessibility programme, with EPUB 3 output across the full backlist.

That proof point makes the strongest CTA for this article:

Do not ask whether a partner can remediate one EPUB. Ask how its QA model behaves at title 10,000.

Final Takeaway

Accessible EPUB backlist remediation is not simply an EPUB 2-to-EPUB 3 conversion exercise.

It combines:

• Catalogue analysis
• Semantic remediation
• Navigation
• Alt text
• Tables
• Accessibility metadata
• Automated validation
• Human QA
• Assistive-technology testing
• Retesting

For large catalogues, use:

Inventory → Sample → Prioritize → Remediate → Validate → Human Test → Retest → Deliver

The goal is not only an accessible title.

It is a repeatable accessible-publishing workflow that can survive catalogue scale.