What Is PDF/A? When You Need It and How to Create It

PDF/A is a version of PDF designed for long-term archiving. It is an ISO standard (ISO 19005) that requires a file to be completely self-contained, with all fonts embedded and no dependence on outside resources, so it will display the same way decades from now. You need PDF/A when a court, government body, archive or employer specifically asks for it. Most everyday PDFs are not PDF/A, and that is fine for normal sharing. To create one, use the "Save as PDF/A" option in a word processor or a dedicated PDF application, then check it with a validator.

ToolMany's PDF tools produce standard PDFs, not certified PDF/A files. This guide explains what PDF/A is so you can choose the right tool for that requirement.

What makes a PDF a PDF/A?

A PDF/A file must follow rules that guarantee it can be reproduced exactly in the future:

• All fonts embedded. The file cannot rely on fonts installed on the reader's computer.
• Device-independent colour. Colours are defined with an embedded colour profile.
• No encryption or passwords. An archive must be able to open the file without a key.
• No external content. No links to fonts, images or other files outside the PDF.
• No audio, video or JavaScript. Active content may not work in future software.
• Standard metadata (in a format called XMP), including the PDF/A version the file claims to meet.

A file is only PDF/A if it meets these rules and declares itself as PDF/A. Renaming a file does not make it PDF/A.

The versions: PDF/A-1, 2, 3 and 4

Within versions there are conformance levels:

• b (basic): guarantees the file looks the same in future.
• a (accessible): also requires tagged structure for accessibility and reliable text extraction.
• u (Unicode): requires all text to be mapped to Unicode, so it can be searched and copied.

If a submission rule says "PDF/A" without a version, PDF/A-2b is a common, widely accepted choice, but check with the organisation.

When do you need PDF/A?

You need it when the recipient requires it, for example:

• court filings in some jurisdictions' electronic filing systems;
• government submissions, such as tax or company registry documents in some countries;
• theses and dissertations for university repositories;
• archiving in records-management systems at companies and public bodies;
• electronic invoices in some standards (based on PDF/A-3 with embedded data).

For emailing a document, uploading a CV or sharing a contract for signature, a normal PDF is fine.

How to create a PDF/A file

From a word processor

• Microsoft Word (Windows): File → Save As, choose PDF, click Options, and tick PDF/A compliant.
• LibreOffice: File → Export as PDF, and on the General tab tick Archive (PDF/A, ISO 19005), choosing the version.
• Google Docs and many other online editors do not offer a PDF/A option at the time of writing; export to a normal PDF and convert with a dedicated tool.

From an existing PDF

Dedicated PDF applications, both commercial desktop software and some free tools, can convert an existing PDF to PDF/A and report problems they cannot fix, such as missing fonts.

Validate the result

A file saved "as PDF/A" can still fail, for example if an embedded image has an unusual colour profile. Organisations that require PDF/A often validate uploads automatically. Free validators, such as the open-source veraPDF project, check a file against the standard and list any problems.

Preparing documents before converting

Many PDF/A problems can be avoided by preparing the source well:

• Use common, embeddable fonts. Some commercial fonts forbid embedding.
• Avoid scanned images without text where the recipient needs searchable text. Use OCR first; see extracting text from images.
• Combine pages before converting. If a submission needs one file, merge first with Merge PDF, then convert the merged result to PDF/A. Merging afterwards with a general tool may remove PDF/A conformance.
• Remove passwords. PDF/A does not allow encryption; unlock a protected file with the PDF password tool if you have the password.
• Check the text layer. Use PDF to Text to confirm the text can be extracted in the right order.

PDF/A vs PDF/X, PDF/UA and PDF/E

PDF/A is one of several ISO subsets of PDF, each built for a different job:

A single file can meet more than one standard at once; a PDF/A-2a or PDF/A-4 file that is also PDF/UA is common in public-sector archives. If a request names PDF/X instead, it comes from a printer, not an archive, and needs different export settings.

Does PDF/A make files bigger?

Often slightly, because fonts and colour profiles are embedded. For text documents the increase is usually modest. Scanned documents are dominated by image size, so preparing images carefully (resolution, greyscale where possible) matters more than the format.

Does editing a PDF/A file break it?

It can. Many editors save changes in a way that no longer meets the standard, and the file may still claim to be PDF/A even though it is not. If you must edit, edit the source document and export a new PDF/A, or re-validate after editing.