Skip to main content
VellumPDF

Convert to PDF/A

A format built to stay readable twenty years from now.

Your files never leave your device

Drop your PDF here

The document to prepare for long-term archiving

How to convert a PDF to PDF/A, step by step

This tool prepares a document for long-term archiving, either by rebuilding the pages as images or by preserving the original text.

  1. Drop the PDF to archive

    Drag the file in, or click to browse for it.

  2. Choose the conversion mode

    “Conforming” mode rebuilds the pages as images and its ISO 19005-2 conformance is validated with veraPDF; “Faithful” mode keeps the text selectable, but its conformance depends on the source document.

  3. Start the conversion

    In Conforming mode, each page is first rasterized then reassembled; in faithful mode, the sRGB output intent and PDF/A-2B metadata are added directly to the existing file.

  4. Read the font warning, in faithful mode

    If fonts the document uses aren’t embedded, they’re named: the most common reason PDF/A validation fails.

  5. Download the converted file

    The resulting PDF/A downloads directly, ready for a submission that requires this format.

Only Conforming mode has proven conformance. Faithful mode improves the file — output intent, identifier, metadata, stripping JavaScript — without converting CMYK colors, flattening transparency or embedding missing fonts: the file is improved, not certified.

Frequently asked questions

What is PDF/A, and why does an administration require it?

PDF/A is a standardised form of PDF (ISO 19005) meant for long-term archiving: everything needed to display the document again in ten years has to be inside the file itself — embedded fonts, colours defined independently of the screen, no dynamic content. That is why an administration, a court or a library can require it: an ordinary PDF may depend on a font installed on your machine and look different elsewhere. VellumPDF produces PDF/A-2B.

What is the difference between “Conforming” and “Faithful” mode?

Conforming mode rebuilds the document from pages rendered as images: no fonts, no dynamic content, so nothing that can break the standard. It is the only mode whose conformance is proven, validated with veraPDF across a varied corpus. Faithful mode keeps the text and its selectability and improves the file as best it can — but the result depends on the source document.

Why does Conforming mode remove selectable text?

Because conformance largely comes down to fonts: PDF/A requires them all to be embedded, and a tool running in the browser cannot retroactively embed a font it does not have. Rendering the pages as images removes the question. The trade-off is deliberate: verifiable conformance rather than hoped-for conformance. If you need a searchable archive, run the file through text recognition afterwards.

Why does the tool report fonts that are not embedded?

Because faithful mode checks every font the document uses and names the missing ones, instead of quietly producing a file that will fail validation. A font that is not embedded is the most common reason for rejection. Two ways out: regenerate the source PDF with font embedding turned on, or use Conforming mode.

Is conformance guaranteed?

For Conforming mode it is verified: the project’s test harness validates the files produced with veraPDF, including a file actually built by the browser. For faithful mode it is not, and we would rather say so: it adds the sRGB output intent, a file identifier and consistent metadata, and strips JavaScript and open actions, but it does not convert CMYK colours, does not flatten transparency and does not embed missing fonts. The file is improved, not certified.