How to Convert PDF to PDF/A for Long-Term Archiving

Converting a PDF to PDF/A turns an everyday document into a self-contained, long-term archival file that will open the same way in ten or thirty years, regardless of what software or fonts exist by then. It's the format required by many courts, tax authorities, universities and record-retention policies across the EU — so if you've been asked to submit a "PDF/A" invoice, contract or thesis, a standard PDF export usually isn't enough.

What Is PDF/A and How Is It Different From a Regular PDF?

PDF/A is not a separate file type — it's a restricted, ISO-standardised subset of PDF (ISO 19005) designed for archiving rather than everyday exchange. Every PDF/A file is a PDF, but not every PDF is a PDF/A. The technical differences that make a file "PDF/A" include:

• All fonts must be embedded, not just referenced, so text renders correctly even if the original font disappears from every computer on earth.
• No encryption, passwords or JavaScript are allowed, since these depend on external systems that could stop working.
• No audio, video or executable attachments — only static, self-contained content.
• Colour must be defined in a device-independent way via an embedded ICC profile, so it doesn't shift depending on hardware.
• XMP metadata is required in a specific structured format describing title, author and creation tool.

In short: a regular PDF is optimised for viewing and printing today; PDF/A is optimised for looking identical decades from now.

Can You Convert Any PDF to PDF/A?

Mostly yes, but not unconditionally. Because PDF/A strips out things like encryption, embedded video and non-embedded fonts, a source PDF that relies on those features needs to be adjusted during conversion, not just repackaged. In practice:

• A password-protected PDF must be decrypted first.
• A PDF using system fonts rather than embedded ones will have those fonts embedded automatically by a decent converter.
• A PDF that already looks "flat" — text, images, embedded fonts, no interactivity — converts cleanly in seconds.
• Scanned, image-only PDFs convert fine but remain non-searchable unless you run OCR first, since PDF/A doesn't add text recognition on its own.

If a file has DRM-style restrictions or heavily depends on JavaScript forms, expect the converter to flatten form fields or drop scripts. That's expected behaviour, not a bug.

How to Convert PDF to PDF/A, Step by Step

The manual route in Adobe Acrobat Pro (File > Save As Other > Archivable PDF) works but requires a paid licence and a "preflight" dialogue most people find confusing. For a quicker path with an ordinary PDF, an online converter does the job:

1. Open Konomic's PDF to PDF/A tool at konomic.io.
2. Upload the source PDF — no account needed, and the file is processed on EU-based servers in Germany, then deleted automatically within an hour.
3. Choose the target conformance level, commonly PDF/A-2b or PDF/A-1b for general use.
4. Run the conversion. The tool embeds fonts, converts colour spaces and strips disallowed elements automatically.
5. Download the converted file and check its document properties — a correctly converted file will show PDF/A compliance in its metadata.

Because the process runs server-side and the original file never needs to sit around in multiple local copies, it's a reasonably tidy way to handle sensitive documents such as contracts or medical records that shouldn't linger on a third party's storage any longer than necessary.

Converting to PDF/A-1a Specifically

PDF/A has three main parts and two conformance levels within each, and PDF/A-1a is the strictest combination. Part 1 (PDF/A-1) is based on PDF 1.4 and is the most widely accepted, especially by government archives. Level "a", for accessible, requires correct logical structure tagging — reading order, headings, alt text for images — on top of the basic archival rules, so the document works properly with screen readers. Level "b", basic, only guarantees visual reproducibility without the accessibility tagging.

To hit PDF/A-1a specifically:

1. Tag the document correctly at the source — in Word or similar tools, use built-in heading styles and add alt text to images before exporting to PDF.
2. Export to a standard PDF from that properly tagged source.
3. Run the PDF/A conversion and select "PDF/A-1a" as the target level rather than 1b.
4. Validate the result, since converters vary in how well they preserve tag structure — a file reporting as PDF/A-1a but lacking proper tags will fail a strict validator.

If your source PDF has no tag structure at all, which is common with scanned documents or PDFs exported from older tools, most converters can only produce PDF/A-1b, not 1a, because accessibility tags can't be reliably invented after the fact.

Validating and Troubleshooting Your PDF/A File

Don't just trust a converter's "success" message. Use a free validator such as veraPDF, the open-source tool recommended by many national archives, to confirm compliance. Common failure points include non-embedded fonts (usually an unusual or licensed font the converter couldn't access), transparency effects like drop shadows or semi-transparent overlays that some older PDF/A levels don't support, and missing colour profiles on images pasted in from external sources.

If validation fails, re-export the source document with simpler formatting or try a different conversion level. PDF/A-2 and PDF/A-3 support transparency and are often easier targets than the stricter PDF/A-1.

Choosing a Conversion Tool

Acrobat Pro, iLovePDF, Smallpdf, Sejda and Konomic all offer PDF-to-PDF/A conversion, and core conversion quality is broadly similar across them since most rely on comparable open-source PDF libraries. The differences that actually matter are file-size limits on free tiers, whether an account is required, and what happens to your document afterwards. Konomic's version skips the signup step and runs on EU servers with automatic deletion within an hour, which is worth knowing if the document you're archiving is a contract, medical record or anything else you'd rather not leave sitting on a server indefinitely.