PDF vs PDF/A
The Portable Document Format (PDF), created by Adobe Systems in 1993, changed the way digital documents were shared and viewed. Its purpose was to ensure that any file would look the same on every device, no matter the system, font, or screen.
In 2005, the need for a version of PDF that could serve as a reliable digital archive led to the creation of PDF/A. Standardized by the International Organization for Standardization (ISO 19005), this format was built for one mission: to keep documents accessible and visually identical for decades.
While a traditional PDF can contain external resources, dynamic elements, and encryption, a PDF/A file must be entirely self-contained. Every font, image, color profile, and metadata element must be embedded within the file. This ensures that the document will appear exactly the same in the future as it does today, even if software or hardware changes.
The main difference lies in purpose. PDF is meant for distribution and interactivity, while PDF/A is meant for preservation and reproducibility.
When to Use PDF/A Files
PDF/A files are ideal when your goal is authenticity and long-term readability. They are commonly used in industries that require strict documentation standards and legal compliance.
Here are some common and modern scenarios where PDF/A is the right choice:
Legal Documents: Contracts, court filings, and agreements that must remain unaltered over time.
Government Archives: Permits, regulations, and historical records preserved for public access.
Medical Institutions: Hospitals and clinics maintaining patient histories and diagnostic reports.
Academic and Historical Archives: Libraries and museums digitizing manuscripts, theses, and cultural artifacts.
Corporate and Financial Records: Reports, invoices, and compliance documents requiring long-term storage.
SaaS Platforms: Companies that offer document automation, such as invoices or reports, can use PDF/A for output that needs to be legally valid and archivable.
Cloud-Based Backup Systems: Services that manage long-term storage of sensitive files can use PDF/A to ensure those documents remain readable regardless of future file format changes.
In short, whenever a file must remain unchanged, authentic, and accessible indefinitely, PDF/A is the right choice.
The 3 Different Types of PDF/A
Over time, the PDF/A standard evolved to meet new archiving needs. There are three main versions, each adding more flexibility while maintaining compliance with ISO standards.
PDF/A-1 (Based on PDF 1.4 – ISO 19005-1:2005)
The original version emphasizes long-term preservation and visual consistency. It prohibits encryption, audio, video, and transparency. All fonts must be embedded, and only device-independent color spaces are allowed. This version is the most restrictive but also the most reliable for long-term archiving.
PDF/A-2 (Based on PDF 1.7 – ISO 19005-2:2011)
This version introduces greater flexibility. It allows layered content, transparency, and the JPEG2000 image format. It also supports digital signatures and attachments between related PDF/A files. PDF/A-2 is suitable for modern workflows that still require full archival compliance.
PDF/A-3 (Based on PDF 1.7 – ISO 19005-3:2012)
The latest version allows the embedding of non-PDF content inside a PDF/A document, such as XML, CSV, or Excel files. This makes it ideal for archiving digital invoices and documents that combine visual content with structured data.
Recommendation: For most modern applications, PDF/A-2 is the best choice. It balances strict archival requirements with more advanced features like digital signatures and transparency.
How Can I Convert PDF to PDF/A
Many modern text editors, including Microsoft Word, LibreOffice, and Google Docs, allow you to save documents directly as PDF/A. For example, in Word, you can go to File → Save As → Tools → Save as type, and then select PDF and check the option for ISO 19005-1 compliant (PDF/A).
If you already have a PDF file or cannot export it directly as PDF/A, you can still convert it from one format to another using several methods.
Using pdforge Free Tool
You can use pdforge’s free online converter to transform your existing PDFs or HTML files into compliant PDF/A versions.
Upload your document.
Choose your desired compliance level (PDF/A-1, PDF/A-2, or PDF/A-3).
Click Convert and download the ready-to-archive file.
pdforge automatically validates metadata, embeds fonts, and adjusts color profiles. It’s fast, accurate, and can also be integrated into automated SaaS workflows through its API.
Using Adobe Acrobat Reader (Pro)
Adobe Acrobat remains the industry standard for creating and editing PDFs. It is always recommended to use the software developed by the same company that created the PDF format in the first place, especially when dealing with batch document generation or enterprise archiving.
To convert your file in Acrobat Pro:
Open your PDF file.
Go to Tools → PDF Standards.
Select Save as PDF/A and choose your desired level.
Save and verify compliance using the built-in validation tool.
This approach guarantees ISO-compliant results and is trusted in professional and legal environments.
Using Other Free PDF to PDF/A Online Conversion Tools
Several free tools provide quick online conversion for users who prefer not to install software:
iLovePDF: Offers a simple drag-and-drop interface for PDF/A conversions.
FreePDFConvert: Lets you choose your preferred PDF/A version and convert multiple files.
While online converters are convenient, they might not always guarantee complete compliance or privacy for sensitive documents. For production environments, use secure, API-based tools like pdforge or on-premise software.
What Is the Pattern PDF/UA
PDF/UA, which stands for Universal Accessibility, is an ISO standard (ISO 14289) focused on accessibility rather than archiving. It ensures that documents can be used by people with disabilities who rely on assistive technologies like screen readers or braille displays.
A PDF/UA file includes:
Proper document tagging that defines structure and reading order.
Metadata for title, language, and author.
Text alternatives for images, charts, and diagrams.
Logical keyboard navigation for accessibility tools.
While PDF/A focuses on ensuring that files remain readable over time, PDF/UA ensures they are readable by everyone, today.
PDF/UA files can be opened using standard readers like Adobe Acrobat Reader, Foxit PDF Reader, or accessibility tools such as NVDA and JAWS. These programs interpret the file’s structural tags to deliver a coherent experience for all users.
PDF/A and PDF/UA are complementary. One ensures permanence and authenticity, while the other guarantees inclusivity and usability.
Final Thoughts
The difference between PDF and PDF/A is not just technical, it is philosophical. PDF is built for flexibility and collaboration, while PDF/A enforces structure, predictability, and permanence.
Understanding how to convert and manage PDF/A files is essential for developers, organizations, and SaaS providers handling sensitive or long-term data. Whether you save directly from your text editor or convert using tools like pdforge, Adobe Acrobat, or other free online tools, making your documents compliant ensures they remain authentic and readable in the years ahead.
As technology continues to evolve, PDF/A remains a digital time capsule. It protects the integrity of information, ensuring that the documents we create today will still be accessible, verifiable, and faithful to their original form decades from now.
