What Is PDF/A? Archival PDF Format Explained

TL;DR

PDF/A is an ISO-standard, self-contained PDF for long-term archiving. It embeds every font, bans JavaScript and encryption, and is required for many legal, government, and healthcare workflows. PDF/A-2b is the safest default.

Why regular PDFs aren't enough for archives

A regular PDF can reference fonts that aren't embedded, link to external files, run JavaScript, or use proprietary encryption. None of that is a problem today — but in 20 years, the font may not exist, the linked file may be lost, the JavaScript engine may be gone, and the encryption key may be unrecoverable. For legal records, government archives, and long-lived corporate documents, that's an unacceptable risk.

What PDF/A actually is

PDF/A is an ISO-standardised subset of PDF (ISO 19005) designed for long-term archiving. It enforces self-containment: every font is embedded, every colour profile is specified, no external references, no JavaScript, no encryption. The result is a file that any standards-compliant viewer can render identically — today, in 10 years, in 50 years. Convert your PDFs to the archival standard with our PDF to PDF/A converter.

PDF/A-1, A-2, A-3, A-4 — which one?

PDF/A-1 (2005) is the strictest and most widely required by governments. PDF/A-2 (2011) adds JPEG 2000, layers, and PDF/A-1 file attachments. PDF/A-3 (2012) allows arbitrary file attachments — popular for embedding source data (e.g. an XML invoice next to its PDF). PDF/A-4 (2020) drops some legacy restrictions. Each level has 'b' (basic), 'a' (accessible, fully tagged), and 'u' (Unicode) sub-conformance levels. When in doubt, use PDF/A-2b — broad support, modern features, no compliance headaches.

When you need PDF/A

You need PDF/A for: government and legal filings, court submissions, long-term contracts, healthcare records, financial audit trails, scientific datasets, and any document an archivist will hold onto for decades. Many regulators (EU eIDAS, US courts, healthcare HIPAA workflows) require PDF/A explicitly.

What you can't do in PDF/A

PDF/A bans: encryption, JavaScript, audio/video, external file references, and unembedded fonts. If your PDF has any of those, conversion will strip them or fail. That's the whole point — archival files must be self-contained.

How to convert

Most modern converters support PDF/A as an output preset. Use our free PDF to PDF/A tool to convert in seconds. For batch jobs, Adobe Acrobat Pro and PDF24's desktop app both produce certified PDF/A. Always validate the output with a tool like veraPDF if compliance matters.

Frequently asked questions

Is PDF/A the same as a regular PDF?

No — PDF/A is a strict subset that bans features that could break in the future (unembedded fonts, JavaScript, encryption, external links). Regular PDF is fine for everyday use; PDF/A is required for long-term archiving.

Which PDF/A version should I use?

PDF/A-2b is a safe modern default. Use PDF/A-1b only if a regulator or court explicitly requires it. Use PDF/A-3 if you need to embed source data (e.g. invoices with attached XML).

Can I edit a PDF/A?

Yes, but editing breaks PDF/A compliance. Make your edits, then re-export to PDF/A using a compliant converter.

How do I check a file is valid PDF/A?

Use veraPDF (open source) or Adobe Acrobat Pro's preflight tool. Both tell you exactly which conformance level your file passes or fails.

Does PDF/A support digital signatures?

Yes — PDF/A-2 and later allow PAdES digital signatures, which is how legally-binding signed PDFs are usually archived.