You know what a PDF is. It's the universal format for sharing documents. But have you ever seen an option to save a file as a "PDF/A"? What does that "A" mean, and when should you use it?
While they look identical, PDF and PDF/A are designed for different purposes. Understanding the difference is crucial for long-term document storage and compliance.
Standard PDF (Portable Document Format)
A standard PDF is built for flexibility and richness. Its goal is to create a document that looks and acts the same way everywhere, but it can contain a wide variety of elements:
- Fonts linked from your computer
- Audio and video content
- JavaScript and other executable actions
- Encryption and digital signatures
This richness is great for interactive documents and presentations. However, its reliance on external resources (like fonts on your computer) makes it a poor choice for long-term archiving. If you open that same PDF 20 years from now on a different computer, the fonts might be missing, or the video codec might be obsolete, changing the document's appearance.
PDF/A (Portable Document Format for Archiving)
PDF/A is a specialized subset of the PDF format designed for one purpose: long-term preservation. It ensures that the document will look exactly the same 5, 50, or 100 years from now, regardless of what software or hardware is used to open it.
To achieve this, PDF/A has strict rules:
- Everything Must Be Self-Contained: All fonts used in the document must be embedded directly within the file.
- No Dynamic Content: JavaScript, audio, and video are forbidden because they can become obsolete or pose security risks.
- No Encryption: To ensure the file can always be accessed, encryption is not allowed.
- Color-Managed: Colors must be defined in a device-independent way.
When to Use PDF vs. PDF/A
| Use Case | Recommended Format | Why? | | ----------------------------------------- | ------------------ | ------------------------------------------------------------------------- | | Sending an invoice or report | Standard PDF | It's a temporary document. Flexibility is fine. | | Creating an interactive presentation | Standard PDF | You need rich media like video and links. | | Submitting a legal document to a court| PDF/A | Courts and governments require PDF/A for long-term, unalterable records. | | Archiving university research | PDF/A | Ensures future researchers can view the work exactly as it was published. | | Storing official records (e.g., deeds)| PDF/A | The document's appearance must be preserved perfectly over decades. |
How to Create a PDF/A
Most modern software, including Microsoft Word ("Save As") and Google Docs ("Print"), gives you an option to save or export as a PDF/A. When creating a document intended for permanent storage, always look for this option in the save/export settings.
For everyday tasks like signing a contract or filling out a form, a standard PDF and a simple editor like Docento.app are all you need. But when your documents need to stand the test of time, PDF/A is the only choice.