# PDF to PDF/A — Convert PDF to PDF/A on Mac

Make archival PDF/A files for courts, governments and long-term records. Part of OneMacTools, 151 private tools in one native Mac app (macOS 26 or later); category: PDF. Runs on your Mac; nothing is uploaded.

PDF/A is the archival version of PDF that courts, tax offices and archives ask for: fonts embedded, colours defined and nothing that depends on the internet. OneMacTools converts to PDF/A-2b (or 1b or 3b) using the open-source Ghostscript engine, which it can install for you.

Page: https://www.onemactools.com/tools/pdf-to-pdf-a · Download: https://www.onemactools.com/download · Pricing: https://www.onemactools.com/pricing

## How to use it
1. **Install Ghostscript once.** If it isn't installed yet, OneMacTools offers to install Ghostscript through Homebrew with one click.
2. **Add the PDF.** Drop one or more PDFs onto PDF to PDF/A.
3. **Choose the standard.** In the right-hand panel, pick PDF/A-2b unless the place you're sending it to asks for another level.
4. **Convert.** Click Convert. Ghostscript embeds the fonts and defines the colours the standard requires.
5. **Check and send.** The file, named “<name> PDF-A”, is saved in a dated folder in Downloads › OneMacTools.

## Options
- **Standard:** PDF/A-2b (recommended), the default, is the most widely asked-for level. PDF/A-1b is the oldest and strictest, for systems that only accept it. PDF/A-3b also allows attached files, as some e-invoicing formats need.

## Tips
- Check what the court, office or archive asks for. If it just says PDF/A, PDF/A-2b is the usual choice.
- If a portal rejects the file, run it through a PDF/A validator, which tells you exactly what it objects to. OneMacTools can't promise every portal will accept the result.
- Colours are converted to RGB with an sRGB profile, so print-ready CMYK files may shift slightly.
- Remove any password first with Remove PDF Password; archival files can't be encrypted.
- Keep your original PDF too. PDF/A conversion can make some files noticeably larger because fonts are embedded.

## Questions
**How do I convert a PDF to PDF/A on a Mac?**
Drop the PDF onto PDF to PDF/A, leave Standard on PDF/A-2b and click Convert. The archival copy is saved in Downloads › OneMacTools.

**What is PDF/A?**
An archival version of PDF designed to look the same in decades to come: fonts are embedded, colours are defined and nothing depends on outside resources.

**Which PDF/A version should I choose?**
PDF/A-2b unless you're told otherwise. Choose 1b only if a system insists on it, and 3b if you need to attach files, as some e-invoicing formats do.

**What does the b in PDF/A-2b mean?**
Basic conformance: the pages are guaranteed to look the same when reopened. It's the level most courts and archives ask for.

**Will a court or government portal accept the file?**
The file is made to the PDF/A standard, but every portal runs its own checks, so we can't promise acceptance. If it's rejected, a PDF/A validator will show why.

**Why do I need Ghostscript?**
Ghostscript is the free, open-source engine that does the conversion. OneMacTools installs it through Homebrew with one click and runs it on your Mac.