An ordinary PDF can depend on things outside the file: a font that is only on the author's computer, a colour setting that differs between devices, a link to external content. Open it in twenty years and it may not look the same. PDF/A is the version of PDF designed to avoid that. It is an ISO standard (ISO 19005) for long-term archiving, and it requires that everything needed to display the document is stored inside the file itself.
That is why courts, government agencies, national archives, universities and many companies ask for PDF/A when you submit filings, theses, tenders or records. The S-PDF PDF to PDF/A converter turns your PDF into PDF/A-1b, PDF/A-2b or PDF/A-3b: fonts are embedded, an sRGB colour profile is added and colours are converted to RGB, so the document is self-contained and displays consistently.
How to convert PDF to PDF/A in 3 steps
- Add your PDFs Select the documents you need to archive or drag them onto the upload box. Password-protected files must be unlocked first with Unlock PDF.
- Choose the PDF/A version Pick PDF/A-2b (recommended) unless your archive asks for something else. Choose PDF/A-1b for the oldest, widest support, or PDF/A-3b if the file may carry embedded attachments.
- Convert and download Start the conversion and download your PDF/A file. Several files arrive as one ZIP, and each one can also be downloaded on its own.
Why use S-PDF for PDF to PDF/A
- Three PDF/A versionsChoose PDF/A-1b, PDF/A-2b or PDF/A-3b to match what your archive or portal requires.
- Fonts embeddedThe fonts your document uses are stored inside the file, so text displays the same on any device.
- Consistent colourAn sRGB colour profile (OutputIntent) is added and colours are converted to RGB.
- Same visual appearanceThe b level is about how the page looks, so your pages keep their layout and content.
- Batch conversionConvert several PDFs to PDF/A at once and download them together or one by one.
- Nothing to installWorks in any modern browser on Windows, Mac, Linux, Chromebook, iPhone, iPad and Android.
PDF/A-1b, 2b or 3b: which one do you need?
| Version | Based on | Choose it when |
|---|---|---|
| PDF/A-1b | ISO 19005-1, the first version | The archive or portal explicitly asks for PDF/A-1, or you need the widest compatibility with older systems |
| PDF/A-2b | ISO 19005-2 | No specific version is required. It is the recommended default and supports newer PDF features such as transparency and layers |
| PDF/A-3b | ISO 19005-3 | The document needs embedded attachments of any type, such as the data file that accompanies an e-invoice |
The rules you received usually name the version: look for wording like "PDF/A-1b" or "PDF/A-2" in the submission guidelines. If they only say "PDF/A", PDF/A-2b is a safe choice. A higher number is not "better" for every archive; it is a newer edition of the standard that allows more features, and some older systems only accept PDF/A-1.
What the "b" means
Each PDF/A version has conformance levels. The b stands for basic: it guarantees that the visual appearance of the document is preserved, so every page will look the same when it is opened in the future. For most archiving and submission purposes, that is exactly what matters.
Stricter levels exist, such as a (accessible), which also requires a tagged structure for screen readers and reading order, and u (Unicode), which requires that all text can be reliably extracted and searched. This tool produces level b. If your requirements specifically say PDF/A-1a, 2a, 2u or 3u, check with the receiving organisation whether level b is acceptable.
Validating and preparing your file
The converter uses Ghostscript and aims for full conformance with the version you choose. Some source files contain things PDF/A restricts, such as damaged fonts or transparency in a PDF/A-1 target, and these are the usual reasons a file fails a strict check. When an archive or court requires formal proof of conformance, check the result with a PDF/A validator such as the free, open-source veraPDF before you submit it. Many submission portals also run their own check on upload.
- Encrypted PDFs cannot be PDF/A, because the standard forbids encryption. Remove the password with Unlock PDF first.
- Scanned documents can be archived as PDF/A, but the text is only a picture. If the archive should be searchable, run OCR PDF first.
- One file, one submission. If the portal wants a single document, merge your PDFs before converting.
Frequently asked questions
What is PDF/A?
PDF/A is an ISO standard (ISO 19005) for long-term archiving. A PDF/A file contains everything needed to display it, including fonts and colour information, so it looks the same years from now.
Which PDF/A version should I choose?
Use whatever your archive or portal specifies. If it only says PDF/A, choose PDF/A-2b. Pick PDF/A-1b for older systems that need it, and PDF/A-3b if the file must carry embedded attachments.
Is the PDF to PDF/A converter free?
Yes. Convert up to 10 files and 50 MB per task, 5 tasks a day, with no signup and no watermark. Pro ($5 a month or $50 a year) allows 50 files and 500 MB per task, unlimited tasks under fair use, and no ads.
Will my document look different after conversion?
It should look the same: the b level is designed to preserve visual appearance. Colours are converted to RGB with an sRGB profile, so files prepared for professional CMYK printing may show slight colour shifts.
How can I check that my file is valid PDF/A?
Open it in a PDF/A validator such as veraPDF, which is free and open source. This is recommended whenever an archive, court or authority requires formal proof of conformance.
Why can't I convert a password-protected PDF?
The PDF/A standard does not allow encryption. Remove the password with Unlock PDF first, then convert the unlocked file.
Can I convert a scanned PDF to PDF/A?
Yes, it will be archived as it looks. To make the text searchable as well, run the scan through OCR PDF before converting to PDF/A.
Is it safe to convert legal or official records here?
Files are transferred over HTTPS and processed in private storage with no public web address. They are never shared or reused, and they are removed automatically one hour after your last action; Delete my files now removes them sooner.
Last updated by The S-PDF team.