Skip to content
PDFZyro

What is PDF/A?

PDF/A is a version of the PDF format standardized for long-term archiving (ISO 19005). A PDF/A file must contain everything needed to display it the same way in the future, such as embedded fonts and colour profiles, and must leave out features that could stop it opening reliably, such as JavaScript, encryption and external content.

Also called: PDF/A archival format, ISO 19005

Updated October 14, 2026 · By the PDFZyro team

How PDF/A differs from a regular PDF

A regular PDF can rely on fonts installed on the reader's computer, run scripts, link to content on the web or be password protected. Any of these can make a file look different, or fail to open, years later. PDF/A removes those risks: fonts are embedded, colours are defined with an embedded profile, and the file carries standard metadata describing itself. It still opens in any PDF reader; it just follows stricter rules.

PDF/A versions and levels

The standard has several parts. PDF/A-1 (2005) is based on PDF 1.4. PDF/A-2 (2011) adds features such as transparency, layers and JPEG 2000 images. PDF/A-3 (2012) also allows any kind of file to be attached, which some electronic invoice formats use. PDF/A-4 (2020) is based on PDF 2.0.

Parts 1 to 3 have conformance levels. Level b (basic) makes sure the pages will look the same. Level a (accessible) also requires a tagged structure for assistive technology, and level u, from PDF/A-2, requires text that can be reliably searched and copied. PDF/A-2b means part 2, level b.

When you need PDF/A

Courts, government agencies, libraries and regulated industries often require PDF/A for filings and records that must be kept for many years. If you're asked for PDF/A, check which part and level is required, and whether the file must pass a validator, a program that checks every rule of the standard.

PDF/A isn't the best choice for every file. Because it can't be encrypted or contain scripts, keep your working copy as a regular PDF and make the PDF/A version when the document is final.

How to save a PDF as PDF/A in PDFZyro

  1. Open the document and choose Tools, then Save as PDF/A, or open PDF/A for archiving with the other optimize tools, next to Compress PDF.
  2. PDFZyro makes a PDF/A-2b copy: it embeds the fonts, adds a colour profile and archive metadata, and removes scripts and attachments.
  3. The copy is saved as a new version. PDFZyro doesn't have a PDF/A validator yet, so the copy is marked as not validated; if a recipient requires a validated file, check it with the validator they use.
Save as PDF/A free

Tools and guides

Related terms

All PDF terms A to Z