What Is PDF/A? (And When You Actually Need It)

PDF/A is the archival cousin of regular PDF — same file, but built to stay readable for decades. Plain-English guide and how to convert in 5 seconds.

PDF/A — the archival format built to outlive software — Same file, built to stay readable for decades

You sent a contract as a PDF, the recipient replied:

"Please send it as PDF/A-2b for our records."

Don't panic. PDF/A is just regular PDF with the unstable parts removed. Here's the short explanation, when you actually need it, and how to convert.

What "regular" PDF looks like under the hood

A normal PDF can include:

Text and images (the obvious stuff)
Embedded fonts — but the file can also point to fonts on the viewer's computer. If those fonts go missing, the text shows in a substitute font.
External media — video, audio, 3D models.
JavaScript — yes, PDFs can run code. Forms with calculations, etc.
Encryption — password-locked PDFs.
Transparency, layers, hidden content — fine on modern viewers, but renders differently on old ones.

Most of that is fine for sending a CV in 2026. None of it is fine for sending a document a court will need to read in 2050.

What PDF/A removes (and why)

PDF/A enforces a few simple rules:

All fonts must be embedded. The file carries its own fonts. Open it on a stone tablet in 2080 — fonts still work.
All colour spaces must be explicit. No "use the system's default colour profile". Colour means the same in 50 years.
No external references. No links to fonts on a server, no embedded video that needs Flash, no anything that requires the outside world.
No JavaScript. No active code. Just a document.
No encryption. Archives need to stay readable, not locked away behind a password somebody will forget.
No transparency or layers (in older PDF/A-1; relaxed in PDF/A-2 and PDF/A-3 — see below).

The result: a PDF that opens identically in 2026, 2040, 2070. Same fonts, same colours, same layout.

The variants you'll hear about

Variant	Year	What's new
PDF/A-1a	2005	Strictest. Requires text to be tagged (accessible to screen readers). For long-term + accessibility.
PDF/A-1b	2005	Strict, no tagging required. Most common everyday choice.
PDF/A-2	2011	Adds JPEG2000, transparency, layers. Smaller files, more modern visuals.
PDF/A-2b	2011	Most common for business and legal today.
PDF/A-3	2012	Allows embedded attachments (Excel, XML inside the PDF). Used in e-invoicing.
PDF/A-4	2020	Cleanest, modern revision. Slowly being adopted.

If you're told just "PDF/A" with no number, PDF/A-2b is the safe default. It's modern enough to be sensible, common enough to be widely supported.

When you actually need PDF/A

7+ years

Legal retention requirement triggers PDF/A in most countries

Decades

How long PDF/A files stay readable, by design

Required

By many courts, regulators, universities, and government archives

5 sec

To convert any PDF to PDF/A with pdfty

Specific cases:

Court filings (US PACER, EU courts, UK Crown Court) often require PDF/A.
Tax / accounting records must be retained 7-10 years; PDF/A is the standard.
Academic theses — many universities require PDF/A submission.
Government archives (US National Archives, UK National Archives, German Bundesarchiv) standardize on PDF/A.
Medical records in many jurisdictions.
E-invoicing — the ZUGFeRD / Factur-X standards in Europe use PDF/A-3 with embedded XML.

If none of those apply to you, you probably don't need PDF/A. Regular PDF is fine for everyday sharing.

How to convert a PDF to PDF/A — step by step

Open the PDF/A tool

Go to pdfty.com/tools/pdf-to-pdfa.

Upload your PDF

Drag in the existing PDF. Free up to 20 MB.

Pick a variant

Default is PDF/A-2b — the right choice for 90% of use cases. If your recipient specified a different variant (1a, 1b, 3b), pick that.

Convert

We embed fonts, fix colour spaces, strip JavaScript and external references. 5-10 seconds for most files.

Download

The result is a PDF/A-compliant file. Viewers (Adobe Reader, Preview, browsers) all open it normally — the difference is invisible to readers but huge for archivists.

Frequently asked questions

Will my PDF look any different after conversion?

No — visually it's identical. PDF/A is about what's inside the file (self-contained fonts, explicit colour profiles, no external refs), not what the page looks like.

Will the file size change?

Usually it gets slightly bigger (5-20%) because we embed all fonts into the file. For PDFs that already had everything embedded, the size barely changes.

Can I still password-protect a PDF/A?

No — PDF/A explicitly bans encryption. The whole point is that archives should stay openable for decades, and a password is a single point of failure. If you need both archival and confidentiality, store the PDF/A inside an encrypted folder (your OS handles that) instead.

Will my hyperlinks survive?

Internal hyperlinks (between pages of the same document) — yes. External hyperlinks (to websites) — they're preserved as text, but PDF/A-1 bans clicking them. PDF/A-2 allows them. So pick PDF/A-2b if clickable links matter.

What if my document has video, audio or JavaScript?

It gets stripped during conversion. That's the point of PDF/A — only the document itself, no active content.

Will it work with scanned PDFs?

Yes — scanned PDFs convert to PDF/A perfectly (an image inside a PDF is already self-contained). If you also need the scan to be searchable later, run OCR before conversion.

How do I verify a file is really PDF/A?

Open it in Adobe Acrobat Reader (free). The blue banner at the top will say "This document claims to be PDF/A-2b." For stricter verification, tools like veraPDF (open-source) check every rule.

What's the difference between PDF/A and PDF/X?

PDF/X is for printing (commercial print houses, magazines). It enforces specific colour profiles and resolution. PDF/A is for archives. They're cousins, not interchangeable.