What Is PDF/A and Why It Matters

PDF was designed to look the same everywhere. PDF/A goes further.

When Adobe created PDF in the early 1990s, the core promise was simple: a PDF should look the same on every computer, every operating system, and every printer. That promise has held up remarkably well. A PDF you created on a Mac in 2005 still renders correctly on a Windows machine in 2026.

But "looking the same" and "being guaranteed to look the same decades from now" are two different things. A regular PDF can reference external fonts that might not be available in the future. It can contain JavaScript that depends on specific viewer behaviour. It can link to external content that may go offline. It can use encryption that requires specific software to open. It can embed multimedia that relies on codecs that may become obsolete.

PDF/A eliminates all of those risks. It is an ISO-standardised subset of PDF specifically designed for long-term preservation of electronic documents. The "A" stands for "archival," and every restriction PDF/A imposes exists for one reason: to make the document completely self-contained, so it can be opened and rendered faithfully decades or even centuries from now, without any external dependencies.

If you work with documents that need to remain readable and legally valid over long time periods, understanding what PDF/A is and when to use it will save you from problems that are expensive and painful to fix after the fact.

What makes PDF/A different from regular PDF

PDF/A is not a different file format. It is a constrained version of the same PDF format, with specific rules about what a PDF/A file can and cannot contain. These constraints are defined in the ISO 19005 standard, and they all serve the same goal: self-containment.

All fonts must be embedded

A regular PDF can reference a font by name and assume the viewer's system has it installed. This works fine today, but there is no guarantee that a specific font will be available on a computer in 2056. PDF/A requires every font used in the document to be fully embedded in the file itself. The glyphs, metrics, and encoding are all stored inside the PDF, so the document will render correctly regardless of what fonts are installed on the viewing system.

No external dependencies

A regular PDF can link to external images, stylesheets, or content. If those external resources disappear, the document degrades. PDF/A forbids any reference to external content. Everything the document needs to render must be contained within the file itself. Images, colour profiles, metadata - all of it lives inside the PDF.

No JavaScript

Regular PDFs can contain JavaScript for interactive forms, calculations, and automation. JavaScript execution depends on specific viewer capabilities that may change over time. PDF/A prohibits all JavaScript. This also has a security benefit - PDF/A files cannot contain malicious scripts.

No encryption

If you encrypt a PDF, you need specific software and credentials to open it. Encryption algorithms can become deprecated, software can become unavailable, and passwords can be lost. PDF/A does not allow encryption, ensuring that the document will always be accessible without special tools or credentials.

Colour profiles must be embedded

Colour appearance depends on colour management profiles. A regular PDF can reference system-level colour profiles. PDF/A requires ICC colour profiles to be embedded in the file, so colours render consistently regardless of the viewing system's colour management configuration.

Metadata must use XMP

PDF/A requires document metadata to be stored in XMP (Extensible Metadata Platform) format. This ensures that title, author, creation date, and other properties are stored in a standardised, machine-readable way that will be interpretable by future software.

The different levels of PDF/A

PDF/A is not a single standard. It has evolved through several versions, each building on the last and aligned with different versions of the underlying PDF specification.

PDF/A-1 (ISO 19005-1, published 2005)

The original PDF/A standard, based on PDF 1.4. This is the most widely supported and most commonly required version. It comes in two conformance levels:

• PDF/A-1b (basic) - Ensures reliable visual reproduction of the document. The file will look the same on any viewer, but text extraction and reflow are not guaranteed to work perfectly.
• PDF/A-1a (accessible) - Adds requirements for document structure, tagged content, and Unicode character mapping. This level ensures that text can be extracted, searched, and read by assistive technologies like screen readers.

PDF/A-1b is the minimum conformance level that most organisations require. It guarantees visual fidelity. PDF/A-1a is preferred when accessibility and text extraction matter, but it is harder to produce because it requires properly tagged document structure.

PDF/A-2 (ISO 19005-2, published 2011)

Based on PDF 1.7, PDF/A-2 adds support for features that were not available when PDF/A-1 was published:

• JPEG2000 compression - Better image compression while maintaining visual quality, resulting in smaller file sizes for image-heavy documents.
• Transparency - PDF/A-1 does not support transparency effects. PDF/A-2 allows them, which means documents with overlapping elements, drop shadows, or semi-transparent graphics can be archived faithfully.
• PDF/A file attachments - A PDF/A-2 file can contain other PDF/A files as attachments. This is useful for bundling related archival documents together.
• Digital signatures - Improved support for embedded digital signatures using PAdES (PDF Advanced Electronic Signatures).

PDF/A-2 also has b and a conformance levels, plus a third level:

• PDF/A-2u - A middle ground between 2b and 2a. It requires all text to be mapped to Unicode (so text can be reliably extracted and searched) but does not require full document structure tagging.

PDF/A-3 (ISO 19005-3, published 2012)

PDF/A-3 is identical to PDF/A-2 with one major addition: it allows embedding of arbitrary file formats as attachments. While PDF/A-2 only permits PDF/A attachments, PDF/A-3 lets you embed spreadsheets, XML data, CAD drawings, source images, or any other file type.

This makes PDF/A-3 popular for electronic invoicing (embedding the structured XML data alongside the human-readable invoice) and scientific publishing (embedding raw datasets alongside the published paper). The embedded files are not required to conform to any archival standard themselves - they are simply preserved alongside the PDF/A document as additional data.

Who needs PDF/A

PDF/A is not something every Mac user needs for every document. But in certain industries and situations, it is either required by regulation or strongly recommended by best practice.

Government and public records

Many government agencies require PDF/A for long-term document storage. Court filings, legislative records, permits, and official correspondence often must be archived in PDF/A format. The US National Archives, the European Commission, and many national archives around the world specify PDF/A for digital preservation. If you submit documents to government agencies, check whether PDF/A is required - increasingly, it is.

Legal and compliance

Law firms and legal departments use PDF/A for case files, contracts, court submissions, and regulatory filings. The self-contained nature of PDF/A ensures that a document presented as evidence will look exactly the same as it did when it was created, with no risk of font substitution or missing content. Some courts mandate PDF/A for electronic filings. Even when it is not mandated, using PDF/A for legal documents is simply good practice because it eliminates questions about document integrity.

Healthcare

Patient records need to be preserved for decades - sometimes for the lifetime of the patient. PDF/A ensures that medical records, imaging reports, lab results, and clinical notes remain readable regardless of how electronic health record systems evolve over time. Healthcare organisations also value the prohibition on JavaScript, since it eliminates a potential attack vector in documents that move between systems.

Financial services

Banks, insurance companies, and financial institutions are subject to record retention requirements that often span seven years or more. PDF/A ensures that statements, contracts, policies, and regulatory filings remain accessible for the required retention period without depending on specific software or fonts.

Archivists and librarians

Digital preservation is the primary purpose of PDF/A, and the people who take preservation most seriously - archivists, librarians, and records managers - were among the first to adopt it. If you are digitising historical documents, creating a personal archive of important records, or managing a corporate records programme, PDF/A is the format that gives you the strongest guarantee of long-term readability.

Anyone who values document longevity

Even outside regulated industries, there are personal situations where PDF/A makes sense. Property deeds, wills, insurance policies, tax records, family documents - anything you want to be absolutely certain you can open and read twenty or thirty years from now. A PDF/A file will never require a specific font, a specific viewer, or a specific operating system to render correctly.

How to create or convert to PDF/A

There are several ways to produce PDF/A files on a Mac, depending on your starting point and your tools.

Export from source applications

Some applications can export directly to PDF/A. Microsoft Word (with the correct settings in Save As), LibreOffice (via the PDF export dialog), and some specialised publishing tools offer PDF/A as an export option. This is the cleanest approach because the application has full control over font embedding, colour profiles, and metadata during the creation process.

Adobe Acrobat Pro

Acrobat Pro can convert existing PDFs to PDF/A using its Preflight tool. It analyses the document for compliance issues, attempts to fix them automatically (embedding missing fonts, converting colour spaces, removing JavaScript), and produces a conforming file. This is a reliable but expensive option, requiring a subscription starting at around $20 per month.

Command-line tools

Tools like Ghostscript can convert PDFs to PDF/A from the terminal. This is useful for batch processing but requires comfort with command-line syntax and careful configuration of colour profiles and font paths. The commands are not intuitive, and incorrect settings can produce files that appear valid but fail strict conformance checks.

Online converters

Several web-based tools offer PDF to PDF/A conversion. The usual caveats about online tools apply: you are uploading your documents to a third-party server. For the kinds of documents that typically need PDF/A compliance - legal, medical, financial, government - uploading to an unknown server is often a non-starter from a privacy and compliance perspective.

Validating PDF/A compliance

Creating a file that you believe is PDF/A is not the same as creating one that actually passes validation. The veraPDF tool (free, open-source) is the industry-standard validator. It checks files against the ISO 19005 specification and reports any conformance violations. If your PDF/A files need to pass regulatory or institutional validation, run them through veraPDF before submission.

PDF/A and Paradise PDF

Paradise PDF currently supports a wide range of PDF operations on Mac - splitting, merging, compressing, OCR, and many more. PDF/A conversion is on the Paradise PDF roadmap as a planned feature. When it arrives, you will be able to convert existing PDFs to PDF/A directly on your Mac, with all processing happening locally - no uploads, no subscriptions, no cloud dependencies.

In the meantime, Paradise PDF's existing tools work well alongside PDF/A workflows. You can use Paradise PDF to merge documents before converting the combined file to PDF/A, OCR scanned pages to create the searchable text layer that PDF/A-1a requires, or organise pages into the correct order before archiving.

Choosing the right PDF/A level

If you need to produce PDF/A files, which level should you target? Here is a practical guide:

When in doubt, PDF/A-1b is the safest choice. It has the broadest software support, the longest track record, and it satisfies the most common archival requirements. Only use PDF/A-2 or PDF/A-3 when you specifically need features they provide.

Related reading

• how PDFs actually work
• flatten a PDF
• view PDF metadata