How to convert a PDF to PDF/A on a Mac
By Himanshu Ranjan · Updated 8 November 2026
To convert a PDF to PDF/A on a Mac, select it and run Convert › PDF to PDF/A in FileDial, which makes PDF/A-2b for archiving. Links and form fields are flattened. It runs locally. PDF/A is an ISO standard for long-term preservation, so check the result against your archive's requirements.
What PDF/A is
PDF/A is an ISO-standardized version of PDF meant for archiving and long-term preservation. It differs from ordinary PDF by prohibiting features unsuitable for archiving. Files must be self-contained, with fonts and color information embedded, so they display the same in future years with different software.
Things it forbids include encryption, JavaScript, executable file launches, audio and video, and references to external content. PDF/A-2 is based on PDF 1.7 and adds features such as JPEG 2000 compression, transparency and layers.
What the b in PDF/A-2b means
Conformance levels describe how much the file promises. The b stands for Basic: it guarantees the visual appearance can be reproduced reliably. The a level adds logical structure, tagging and language information to help screen readers. The u level is basic plus Unicode mapping for text.
FileDial produces PDF/A-2b. That is the right level for most office archiving where the goal is that the pages look the same in twenty years. If you need accessible tagging, a tool that produces PDF/A-2a or checks tags is needed, and FileDial's note does not claim it.
Convert with FileDial
Convert a copy, because the process changes the file by design.
- Select the PDF in Finder.
- Hold the right Option key to open the dial and choose the Convert category.
- Release on Convert › PDF to PDF/A.
- Open the result beside the original. Check pages visually, then keep both files.
What changes, and what it costs you
The tool's note is explicit: links and form fields are flattened. That follows from the standard's emphasis on a fixed, self-contained page. A fillable form stops being fillable and links stop being clickable, so archive the filled-in, finished version and keep a working copy separately.
Embedding fonts and color data can make a file larger. If size matters, compress before converting, not after, because recompressing a PDF/A file with a general tool may undo its conformance.
- Links and form fields are flattened.
- Fonts are embedded, so size can grow.
- Encryption is not allowed: remove a password first.
- Keep a working copy for editing.
A worked example: an invoice archive
A small business wants every invoice from the year stored as PDF/A-2b. The practical routine: first gather the final versions, since fillable fields will be flattened. Second, remove any passwords. Third, select the whole folder and run Convert › PDF to PDF/A once; FileDial works in batches, writing a converted copy beside each original.
Then spot-check: open three PDFs, one short, one long, one with a scanned receipt attached. Confirm the pages look the same, then move the originals to a separate folder and store the PDF/A copies in the archive. If an auditor or client names a validator, run their check on a sample before converting the whole year; the standard has several parts and levels, and a tool that says PDF/A-2b does not automatically satisfy a rule that asks for something else.
Some archives, courts and government bodies ask for PDF/A, and each sets its own rules about version and level. Ask what they require before converting. The Library of Congress describes PDF/A-2 as part of ISO 19005-2, which is useful if you need to cite the standard. We cannot promise that a converted file will pass any particular body's validator; if it is mandatory, run their validation.
Scans in an archive
A scanned page is only a picture, so it cannot be searched in twenty years unless you add text now. Run OCR › Make searchable first, which adds an invisible text layer to pages that have none, then convert to PDF/A. Doing it in that order means the archived file keeps both the exact look of the page and the words for search.
Also check the scan resolution. A low-quality scan will be preserved perfectly, but it will still be a low-quality scan. 300 dpi is a common target for text documents; a rescan is cheaper now than after the paper is gone.
Honest alternatives
macOS Preview does not export PDF/A in its documented menus, so there is no built-in way we can point to. Many apps from other vendors do offer PDF/A export, and some are paid. If you only need a stable, readable file for yourself, a normal PDF kept in two places is also reasonable; PDF/A matters when a third party demands it or when you expect to keep the file for decades.
Archives hold the documents that matter most, so uploading them to a converter is a poor trade. FileDial converts locally and works with Wi-Fi off.
Questions
Is PDF/A the same as a normal PDF?
It is a restricted version. PDF/A forbids features that can break long-term display, such as encryption, JavaScript, linked fonts and external content, and requires fonts to be embedded. Most viewers open it like any PDF, but form fields and links may be flattened.
Which PDF/A level does FileDial create?
Convert › PDF to PDF/A makes PDF/A-2b, the basic conformance level that preserves the visual appearance of the page. It does not claim the accessible a level. If your archive requires a different level or a validation report, check their rules.
Can I convert a password-protected PDF to PDF/A?
Not directly, because PDF/A does not allow encryption. If you know the password, remove it first with Sign & Lock › Remove password…, then convert the unlocked copy. Keep the protected original if you still need it for other purposes. Check the result before relying on it.