How to Convert a PDF to PDF/A for Archiving

By Michael Peters · Published April 16, 2026 · Last updated April 16, 2026 · 9 min read

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Quick summary

You can also convert a PDF to PDF/A online for free using Mapsoft's PDF Hub — no installation required.

What PDF/A requires

PDF/A (ISO 19005) is a subset of PDF designed for long-term archival. It's not a different format — a PDF/A file is still a valid PDF — but it forbids features that depend on external resources or can't be rendered reliably decades from now.

• All fonts embedded. If a font is referenced but not included, the document depends on the reader having that font installed. Not acceptable for archival.
• Colour-managed. Device colour spaces (DeviceRGB, DeviceCMYK) must either be replaced with ICCBased profiles or the document must declare an output intent.
• No encryption. An encrypted PDF depends on key management that may not exist in 50 years.
• No external content. JavaScript, external links as the primary means of access, references to files outside the PDF, and embedded multimedia are all restricted.
• Proper metadata. An XMP packet declaring the PDF/A conformance level (1b, 2b, 3b, etc.) is required.
• Transparency is forbidden in PDF/A-1, permitted in PDF/A-2 and later.
• Embedded files are forbidden in PDF/A-1 and -2, permitted in PDF/A-3.

For full coverage of what each conformance level allows, see our PDF/A standard post.

Which conformance level?

• PDF/A-1b (basic, ISO 19005-1:2005). Most widely supported. No transparency, no embedded files, no JavaScript. Good for strict archival of simple documents.
• PDF/A-2b (ISO 19005-2:2011). Adds transparency, layers, digital signatures. Most common target today for moderately complex documents.
• PDF/A-3b (ISO 19005-3:2012). Adds embedded files. Used for invoices that carry their source data (e.g. ZUGFeRD).
• -a suffix (PDF/A-1a, -2a, -3a) requires full accessibility — tagged structure and a mapping to Unicode. Much stricter. Use when accessibility is a requirement.
• -u suffix (PDF/A-2u, -3u) requires all text to be mappable to Unicode but doesn't require full tagging. A middle ground.

For most archival use cases, PDF/A-2b is the right target. Pick PDF/A-1b only if you're handed a strict requirement; PDF/A-3b when your workflow includes embedded data files; the -a suffix when accessibility compliance is required.

Methods

Method 1 — Adobe Acrobat Preflight

Acrobat Pro has the most capable PDF/A tooling. File → Save As Other → Archivable PDF (PDF/A) triggers a Preflight pass that:

• Embeds all used fonts (or warns if a font can't be embedded).
• Converts device colour spaces to ICCBased using a chosen profile.
• Adds the output intent and XMP metadata for the conformance level.
• Removes encryption and restricted features.
• Flattens transparency if targeting PDF/A-1.

Acrobat's Preflight reports any issues that can't be automatically fixed. Common blockers: fonts that prohibit embedding (rare; some legacy fonts), unsupported image compression, or transparency that can't be cleanly flattened.

Method 2 — Online, free

Mapsoft's Convert to PDF/A tool handles common conversion cases in the browser. Suitable for routine documents without complex fonts or colour issues.

Method 3 — Command line (Ghostscript)

Ghostscript can produce PDF/A output directly:

• gs -dPDFA=2 -dBATCH -dNOPAUSE -sProcessColorModel=DeviceRGB -sDEVICE=pdfwrite -sPDFACompatibilityPolicy=1 -sOutputFile=output.pdf pdfa_def.ps input.pdf
• The pdfa_def.ps file defines the output intent; Ghostscript ships with a sample you can customise.

Ghostscript is powerful but exacting — the configuration is verbose and small mistakes produce non-conformant output. For routine work, Acrobat or online tools are simpler.

Method 4 — Validation

After conversion, validate the output with a PDF/A validator:

• veraPDF is the industry-standard open-source validator, maintained by the PDF Association. It reports specific clauses the document fails.
• Acrobat's Preflight can validate against PDF/A-1b, -2b, -3b, and the -a variants.
• Mapsoft's Analyze PDF reports declared conformance and flags common issues.

What breaks during conversion

• Encrypted PDFs must be decrypted first. Use the owner password to unlock the PDF, then convert to PDF/A.
• Transparency must be flattened for PDF/A-1. See our flattening guide. PDF/A-2 and later preserve transparency.
• JavaScript is stripped. Interactive PDF forms that rely on JavaScript won't work after conversion. Consider flattening forms first.
• External links become informational. Links to external URLs are allowed but shouldn't be the primary means of accessing information.
• Multimedia is removed. Embedded video and audio aren't permitted in PDF/A.
• Some fonts may not embed. Fonts with restrictive licence bits can refuse embedding. In practice this is rare; most Adobe, Microsoft, and open-source fonts embed cleanly.

Frequently Asked Questions

What is PDF/A?

An ISO-standardised subset of PDF (ISO 19005) designed for long-term archival. Every font is embedded, all colour is managed, no encryption, and XMP metadata declares the conformance level.

Which PDF/A version should I use?

PDF/A-2b is the standard target for most archival work today. Use PDF/A-1b for strict legacy compliance, PDF/A-3b when your archive needs to carry embedded source data, or the -a variants when full accessibility is required.

Can any PDF be converted to PDF/A?

Most can. The usual blockers are encryption (remove first), fonts with restrictive embedding flags (swap for similar fonts), and transparency (flatten if targeting PDF/A-1). Complex interactive forms may lose functionality.

How do I verify a PDF is valid PDF/A?

Use a validator: veraPDF (open source), Adobe Acrobat's Preflight (Verify Conformance), or an online analyser. They report specific clauses of the standard that the document fails.