A court portal, a public tender or a university library asks you to send "a PDF/A file". Your document is already a PDF, so what is the difference, and how do you make one without buying software? This guide explains PDF/A in plain words.
PDF vs PDF/A: what is the difference?
PDF/A is an ISO standard (ISO 19005) for documents that must stay readable for decades. Every PDF/A is a PDF, but with stricter rules:
- Everything is inside the file. Fonts and a colour profile are embedded, so the document doesn't depend on what is installed on the reader's computer.
- Nothing depends on the outside world. Scripts, links to outside content, audio and video are not allowed.
- No encryption. An archive must open without a password, years from now.
- Metadata is required, in a standard format (XMP), so archives can catalogue the document.
An ordinary PDF may follow some of these rules by chance; a PDF/A promises to follow all of them, and says so in its metadata.
PDF/A-1, PDF/A-2 and PDF/A-3
- PDF/A-1 (2005) is the first and strictest version: no transparency, no layers.
- PDF/A-2 (2011) is based on a newer PDF version and allows more features, such as JPEG 2000 images. It is the version most portals ask for today.
- PDF/A-3 (2012) is PDF/A-2 plus attached files of any type, used for example for e-invoices that carry their data as XML.
Levels a, b and u
- b (basic): the pages look exactly right, now and in the future. This is what most organisations require.
- u (Unicode): b, plus the text can be reliably searched and copied.
- a (accessible): u, plus a full structure (headings, reading order, alternative text) for screen readers.
If the instructions only say "PDF/A", PDF/A-2b is usually the safe choice.
Who asks for PDF/A?
- Courts and e-filing systems in many countries.
- Public tenders and government records offices.
- Universities, for theses and dissertations.
- Companies that must keep invoices, contracts and HR files for many years.
How to convert a PDF to PDF/A for free
- Open PDF to PDF/A and choose your PDF.
- Choose Standard (150 dpi) for most documents, or High (300 dpi) for fine print and drawings.
- Click Convert to PDF/A and download your PDF/A-2b file.
GrovePDF stores each page as a high-quality picture and keeps its text as invisible, searchable text, so you can still search and copy from it. The conversion runs in your browser: the document is never uploaded.
Before you send it
- Fill in forms and sign the document first: links, form fields and attachments are removed in PDF/A.
- Several documents? Merge them first, then convert the merged file.
- Check the size limit: High quality makes bigger files.
- If the organisation uses a strict validator such as veraPDF, check the file there before the deadline.