PDF documents may include general information, such as the document’s title, author, and creation and modification dates. Such information about the document (as opposed to its content or structure) is called metadata and is intended to assist in cataloguing and searching for documents in external databases.

Metadata plays a tremendous role in modern PDF files, especially in accessibility, document management and AI-based document processing. In PDF files metadata is commonly stored using XMP (Extensible Metadata Platform) package, directly embedded into the document.

Document title and accessibility

Well-Tagged PDF (WTPDF) declarations are metadata, embedded in PDF 2.0 files within the XMP metadata, that assert a document’s conformity with WTPDF 1.0 requirements for accessibility or content reuse. Developed by the PDF Association, these declarations allow software to identify if a file is optimized for assistive technology (similar to PDF/UA-2) or for structured data extraction.

The title helps users understand the purpose of the document before reading its content. Screen readers and other assistive technologies often announce the title when the PDF is opened.

For example:

“Accessibility Report 2026”
“PDF4WCAG PDF Accessibility Checker”

are significantly more useful than:

“doc.pdf”
“pic001.pdf”

PDF/UA identification metadata

In accessible PDFs, XMP metadata may also contain identification information about conformance standards. There are several mechanisms at work here: one used by PDF/UA, another by WCAG. Both are important, as the document may conform to both PDF/UA and PDF/UA, as the latest LaTeX-generated Tagged PDFs do.

This metadata allows validators and accessibility tools to determine whether the document claims compliance with standards such as: PDF/UA and WCAG.

Additional metadata fields

XMP metadata also may contain valuable document information, including: creation and modification date, author or organization, producer and creator tool, language information.

Metadata provides assistive technologies with an initial description of the document before content navigation begins. Without proper metadata, accessible PDFs lose important semantic and usability information.

What PDF4WCAG checks

PDF4WCAG checks:

• dc:title is present and not empty.
• The PDF/UA or WCAG compliance declarations, if the document is validated against PDF/UA or WCAG profiles respectively. These declarations are recommended, but not mandatory for WCAG.
• The XMP package is properly attached to the document catalog.

Accessible PDFs should contain a meaningful dc:title. More advanced workflows should also include standardized identification metadata and descriptive document properties to support both human users and machine processing systems.

VeraPDF 1.30.2 is out now. This patched release is in accordance with a new security policy adopted by veraPDF.

This release comprises the following fixes:

• Secure XML parser for RichText values and XFA
• Secure PostScript parser for ToUnicode CMaps and PS Type1 fonts

To learn more about the new fixes and features, read the release notes. To read more about these vulnerabilities, read the advisories 1 2 3 4 5.

These updates continue to develop veraPDF in alignment with the recent European Cyber Resilience Act, which aims to make devices and software safer by implementing more rigorous cybersecurity, documentation, and vulnerability reporting requirements.

Download

Click here to download: veraPDF 1.30.2

or pull the latest Docker images verapdf/rest and verapdf/cli.

Please report any bugs on the veraPDF issue tracker on GitHub or contact us with any feedback or questions.

About veraPDF

veraPDF is an open-source PDF/A validator covering all parts of the PDF/A and PDF/UA (Matterhorn Protocol Machine failure conditions) standards. Originally funded by the PREFORMA project, veraPDF has been sustained and maintained by the Open Preservation Foundation since 2017. Dual Lab provides active user support and carries out maintenance and bug fixes. The PDF Association’s PDF/A Technical Working Group continues its role in resolving ambiguities arising from veraPDF’s usage in the field.

Dual Lab announces the release of PDF4WCAG Accessibility Checker 1.10, introducing usability enhancements, expanded localization support, and new document inspection panels.

PDF4WCAG is a professional accessibility validation solution for PDF documents, designed to support compliance with PDF/UA, WCAG, and WTPDF accessibility requirements. It is powered by the veraPDF validation architecture and is identical to veraPDF in Machine verifiable checks of PDF/UA and WTPDF validation profiles.

What’s new in Version 1.10

Enhanced localization and user experience

PDF4WCAG 1.10 improves interface usability and multilingual support:

• Redesigned switching between technical terminology and user-friendly language, providing a more intuitive experience for both accessibility experts (developers) and non-technical users.
• Added support for German and Dutch interface localizations.

Improved zoom and navigation controls

Accessibility issue navigation has been refined for better usability:

• Enhanced zoom behavior for small issue regions and error highlights.

New inspection panels

PDF4WCAG 1.10 introduces several new analysis panels to provide deeper document insights:

Annotations panel

Inspects PDF annotations, comments, hyperlinks, form controls, and other interactive elements relevant to accessibility and usability evaluation.

Metadata panel

Displays document metadata including:

• document title
• author information
• document language
• accessibility properties
• PDF/UA-related metadata entries

Fonts panel

Provides detailed analysis of:

• embedded fonts
• font types and subsets
• encoding information

Persistent user preferences

PDF4WCAG now preserves user configuration settings between sessions, improving workflow continuity and efficiency. Persisted settings include:

• selected interface language
• active filters
• right-side panel state and opened sections
• structure tree role map visibility
• auto-scaling preferences

CLI enhancements

The command-line interface has been extended with initial support for additional validation profiles:

• WCAG Machine
• WCAG Machine & Human

These profiles are now available under paid commercial licenses on the PDF4WCAG website.

Public API documentation

A new public documentation section is now available. API is available  under paid commercial licenses on the PDF4WCAG website.

Integration API Beta testing

The PDF4WCAG Integration API is in the process of beta testing. The API is designed to simplify integration of accessibility validation workflows into enterprise systems, document processing pipelines, and third-party accessibility platforms.

This webinar, offered by the members of the LaTeX Project LWG, introduces the PDF Association’s recently-published Best Practice Guide: Math in PDF and takes questions from attendees.

Date & Time: 08:00 ET 11:00 ET 17:00 CET

Topics Covered
Why we’re doing this: poor user experience when reading math
Why PDF 2.0 changes everything
A (brief!) introduction to MathML
Relevant standards and the PDF Association’s new guidance
Implications for publishers and developers

The presentation will consume approximately 25-30 minutes and will be followed by live Q&A.

Presenters

• David Carlisle, LaTeX Project & editor of MathML at W3C
• Boris Doubrov, Dual Lab & chair, LaTeX Project LWG
• Frank Mittelbach, LaTeX Project
• Neil Soiffer, creator of MathCAT, co-chair of the Math WG at W3C

Registration

Register for the webinar!

PDF artifacts are non-semantic visual elements introduced during document generation, rendering, scanning, or OCR processing. In AI pipelines, these artifacts reduce extraction quality and negatively impact downstream tasks such as embeddings, retrieval, and LLM reasoning.

Typical PDF artifacts include:

• page header/footer
• table headers for multi-page tables
• decorative elements interpreted as content

Artifacts should generally be ignored by assistive technologies such as: screen readers, text-to-speech systems, accessibility APIs, AI semantic extraction pipelines.

This concept is very similar to decorative elements in HTML accessibility.

For example, in HTML: decorative images use alt=””, layout containers may use ARIA presentation roles, CSS-generated visuals are ignored semantically. In PDFs, the equivalent mechanism is marking content as an Artifact.

By the way artifacts play a critical role in PDF/UA compliance and screen reader usability. Without proper artifact handling, assistive technologies may read decorative or repetitive content aloud, creating confusion and misunderstandings for users.

Modern accessibility validation tools such as PDF4WCAG Accessibility Checker help identify these issues and ensure PDFs correctly distinguish meaningful content from decorative elements.

The core requirement of both PDF/UA and WCAG is that every piece of content must be designated either as an artifact or as part of the structure tree nothing can be left. This is exactly what PDF4WCAG verifies.

Sample of Artifact errors after PDF4WCAG validation

PDF 2.0 and richer artifact semantics

PDF 2.0 (ISO 32000-2:2020) brought significant improvements to the handling and definition of artifacts compared to previous versions.

Key improvements to the Artifact model in PDF 2.0 include:

• Standardized Tagging: PDF 2.0 provides clearer, more robust mechanisms for marking items as artifacts, especially in tagged PDF, reducing ambiguity for accessibility tools.
• Reduced Vague Wording: It addresses ambiguities in earlier PDF 1.7 specifications, providing clearer rules for how developers and software should handle artifacts.
• Better Annotation Handling: Annotations and their relation to structural elements are better defined, reducing issues where background decorations or marginalia are misidentified as content.
• Improved Structural Hierarchy: It clarifies how artifacted content can interact with the document structure tree, particularly regarding how tags should be ordered or ignored, which was a point of ambiguity in older standards.

To sum it up, proper use of artifacts is one of the foundational concepts of PDF accessibility.
A well-structured accessible PDF must clearly separate: meaningful semantic content and decorative or auxiliary presentation elements.

As PDF accessibility evolves, especially with PDF 2.0 semantics and AI-driven document processing, artifact classification becomes increasingly important not only for accessibility specialists, but also for developers, publishers, and AI engineers building intelligent document systems.

PDF Week comes three times each year; twice for “in-person” events and once online, in a series of meetings that (actually) takes about two weeks.

The in-person PDF Weeks offer attendees a variety of opportunities, including:​

• Engaging directly with industry peers, international representatives and institutional end-users
• In-person participation in the industry’s Technical and Liaison Working Group meetings
• The opportunity to observe and contribute to ISO standardization processes

The event is designed to foster connections between ongoing technical activities within the PDF Association and broader ISO standardization efforts.​

Boris Doubrov is Chair of these communities: LaTeX Project LWG and PDF/A TWG.

Here is a short summary of the week.

v1.30 release of the veraPDF and Arlington tools are out now!

The new version addresses technical depth and various real world issues reported by the community. veraPDF is an open-source, industry-supported PDF/A and PDF/UA (Machine checks) validator and part of the OPF reference toolset. The Arlington PDF Checker is an open-source PDF checker based on the Arlington PDF Model.

Validation

• (PDF/A-4, PDF/UA-2) added validation of pdfaid:rev and pdfuaid:rev
• (PDF/UA-2, WTPDF-1) permit math to be not necessarily an immediate child of Formula structure element
• (PDF/UA-2, WTPDF-1) limited PDF/UA-2 8.10.1 and 8.10.2 clauses to Widget annotations used as the appearance of interactive form fields.
• (PDF/A-1) fixed matching date validation in case any dates are missing in the XMP metadata.
• (PDF/UA-1,2, WTPDF-1) permitted top left cells with no Scope in Table structure element.

PDF Parser

• Fixed runtime exceptions in cases of invalid data structures

Core library

• End of PDFBox support
• Added support for Java 25.
• Added automatic module names to the MANIFEST files.
• Fixed thread safety issues.

VeraPDF Installer

• Added a new option to install CLI only, (no GUI included).
• Removed sources of validation profiles and the model from the installer.

Arlington features

• Implements the Arlington model as of the release date
• Upgraded veraPDF parser to version 1.30.1 RC
• Fixed retrieval of PDF version via the Version entry in the Catalog
• Added auto-detect for ISO_19005_3 and WTPDF extensions
• Fixed issues in processing merged annotations and fields

Security

• Included the fix for GHSA-72hv-8253-57q

Read the release notes to learn more about the new fixes and features.

Download

veraPDF v1.30 can be downloaded here: veraPDF 1.30. Release builds are available in the release folder. Developers can use the veraPDF software libraries in their Java projects via Maven Central, an established distribution platform for Java software.

Docker images for veraPDF are also available. The containerised version of the command-line application is named verapdf/cli, and the REST application is called verapdf/rest.

Arlington v1.30 can be downloaded here: Arlington 1.30. Again, older builds can be found in the release folder and on Maven Central.

Web demonstrators are available at demo.verapdf.org and arlington.verapdf.org, respectively.

We invite the community to download and test the release. Please report bugs on the veraPDF issue tracker on GitHub.

About veraPDF

veraPDF is an open-source PDF/A validator covering all parts of the PDF/A and PDF/UA (Matterhorn Protocol Machine failure conditions) standards. Originally funded by the PREFORMA project, veraPDF has been sustained and maintained by the Open Preservation Foundation since 2017. Dual Lab provides active user support and carries out maintenance and bug fixes. The PDF Association’s PDF/A Technical Working Group continues its role in resolving ambiguities arising from veraPDF’s usage in the field.

Improved Accuracy

Fixes in PDF/UA validation to align with latest technical discussions within TWGs of PDF Association and veraPDF improvements:

• permit Math to be not necessarily an immediate child of Formula structure element;
• improve glyph name calculation for Type1 and TrueType fonts;
• adjusted validation of the PDF Table structure element.

Missing translations of error messages have also been added to improve clarity across languages (Dutch, German, English).

Enhanced User Experience

Error preview filters have been reworked for more convenient error inspection. 

Export Validation Results: users can export validation results as PDF for client reporting, documentation or internal audits purposes. Just click on the Export results on the Summary page.

One-Click Refresh: users can reupload and repeat the analysis of the document in one click (Web) or just via Refresh button in the Desktop version. 

GitHub and collaboration: PDF4WCAG now includes a direct link to its GitHub repository within the feedback popup, inviting developers and users to contribute to the tool’s roadmap.

The ability to use PDF4WCAG command line in the console (paid subscription).

Commercial use of PDF4WCAG: the commercial use of Desktop version and CLI automation is available in the annual subscription for just 299 EUR / 359 USD (excl. taxes). 

This release 1.8  reflects our ongoing commitment to providing precise, standards-aligned accessibility validation and a smoother user experience for organizations working toward WCAG and PDF/UA compliance.

Roadmap Update

We’re excited to announce the start of beta testing for the PDF4WAG Integration API. If you’re interested in participating as a beta tester, please send us your request to info@pdf4wcag.com.

Dual Lab Launches Quarterly Reports on PDF Accessibility Trends based on Common Crawl data

Dual Lab announces the upcoming publication of a new analytical report on PDF Accessibility Trends from  the Common Crawl dataset.  Such deep analytical reports will be released quarterly and will provide data-driven insights into global PDF trends. The first report  analyzes 15 million PDF documents from the CC-MAIN-2026-04 Common Crawl archive.

Mild growth of Tagged PDFs share

As a preview we present a sample report showing the share of Tagged PDFs among all PDFs in the Common Crawl dataset, grouped by the document creation month.

Our analysis shows a mild increase in the proportion of tagged PDFs over the past three years. The share has been growing by approximately 1.5 percentage points per year, surpassing the significant milestone of 50% in mid-2025.

This means that today, more than half of newly created PDF documents appearing in the Common Crawl archives include structure tree with semantic information.

Why Tagged PDFs Matter

Tagged PDFs contain a structure tree that defines headings, paragraphs, tables, figures, and other semantic elements. This structure is essential for:

• The ability of Screen readers to understand the document
• Logical reading order
• Compliance with accessibility standards such as PDF/UA
• Alignment with WCAG requirements

The growth in tagged documents indicates a positive global shift toward better structured and potentially more accessible PDF publishing.

Trend in the Share of Tagged PDFs Among All PDFs

Dual Lab analyzed 15 millions of PDF documents from the Common Crawl dataset CC-MAIN-2026-04 to examine how the share of tagged PDFs has changed over time.

The results show a clear rising trend over the past three years. The proportion of tagged PDFs documents containing a structural tag tree has increased steadily by approximately 1.5 percentage points per year.

A key milestone was reached in mid-2025 (July), when the share exceeded 50% for the first time. This indicates that more than half of newly created PDF documents indexed in Common Crawl now include structural tagging.

The growth reflects broader adoption of structured document generation tools and increasing awareness of accessibility and machine-readability requirements. While the trend is positive, continued monitoring is essential to evaluate not only the presence of tags but also their structural quality.

Reports by Dual Lab

Dual Lab aims to provide objective data that supports users, accessibility experts, and organizations working toward more inclusive digital content.

The first full report will be published soon. 

Reports will be available: Dual Lab website, PDF4WCAG website (the PDF Accessibility validation tool developed by Dual Lab), Google Group Dual Lab Dual Lab Reports on PDF Accessibility Trends; Discord server; our channels in X and Linkedin.