PDF/A

Definition

PDF/A is an ISO standard that restricts PDF to what long-term archiving requires: fonts must be embedded so the text always renders, no content may depend on an external resource, encryption is not allowed, and the file carries standardized XMP metadata describing itself. Several conformance levels exist — commonly 1b, 2b, and 3b — and a file that claims PDF/A should be validated, because claiming is not the same as conforming.

Example

A tax filing a company must keep readable for the statutory retention period. If the original PDF referenced a font that is no longer installed anywhere, the document breaks when it is opened years later. Converted to PDF/A, the font is embedded in the file, so the document renders identically on any machine at any time.

In the PDFLean tools

• convert a PDF to PDF/A — converts to the 1b/2b/3b levels with embedded ICC color profiles
• validate PDF/A compliance — checks a file against the standard and reports what fails

Related reading

• PDF/UA (Accessible PDF) — the sibling standard for accessibility rather than archiving
• Preflight — the print-side counterpart of compliance checking
• Archive a Year of Invoices — the scenario where PDF/A is the destination format