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PDF/A Conversion Library: ISO-compliant PDF to PDF/A

Convert your PDF files and documents to PDF/A, the ISO standard for long-term archiving.

PDF/A files created with GdPicture.NET are ISO-compliant.
Converted files are fully searchable and keep a reasonable size thanks to the many compression techniques supported in GdPicture.NET.
The PDF SDK also includes a PDF/A validator.

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PDF/A conversion engine

The PDF/A standard

PDF/A is the electronic document file format for long-term preservation. Its purpose is to ensure that electronic documents can be viewed and reproduced exactly the same way in the future, no matter which software is used.

For this reason, the document must contain all necessary elements (fonts, color profiles, a digital signature if it is present in the original document) for an authentic reproduction, but it may not contain any references to external content or resources.

Learn more

Challenges of PDF/A conversion

Each format conversion has its challenges and PDF/A conversion has its fair share. First, the standard was not written with conversion in mind, and then in many cases, understanding the format is not sufficient and several conversion strategies are required.
Some of the challenges include:

  • Fonts conformance (non-embedded fonts, incorrect font definitions, inconsistent glyph metrics)
  • Prohibited content (JavaScript, external content references, embedded files, forbidden annotation types)
  • Colorspace conformance ( device-dependent colorspaces, incorrect colorspace definitions)
  • Metadata conformance (metadata does not conform to the XMP Specification)


  • Converts 100+ formats to PDF/A
  • Native PDF/A converter
  • All PDF/A substandards are supported
  • Conversion by direct modification
  • Conversion by vectorization
  • Conversion by rasterization

The importance of validation

Because of the complexity of PDF document format, it is very important to validate if all the PDF/A specification requirements are met. To address this issue many PDF/A validators have been introduced and the validation results may vary when handling specific types of PDF/A documents.

To be certain that the files created by the GdPicture.NET PDF/A converter engine are compliant with the ISO standard, we have developed a PDF/A validator.

The GdPicture.NET PDF/A validator provides:

  • Conformance validation for all PDF versions:
    1. PDF/A-1 (ISO 19005-1:2005)
    2. PDF/A-2 (ISO 19005-2:2011)
    3. PDF/A-3 (ISO 19005-3:2012)
    4. PDF/A-4 (ISO 19005-4:2020)
  • It automatically determines the claimed conformance of the document.
  • It provides both a basic validation result or a detailed machine-readable report (XML).

The engine analyses and validates the following elements:

  • PDF structure
  • Lexical, syntactic, and semantic levels
  • Metadata
  • Fonts
  • Color space
  • Other properties

Test our PDF/A validation engine with your documents:

Areas of use

Many industries have been using PDF/A documents since the release of the first version of the ISO standard in 2005, because they have legal archiving needs:

However, with the digitization process spreading worldwide the need and requirement for using, thus archiving electronic documents like invoices is growing and is now often made mandatory by many countries’ legislations for all organizations.

Try our PDF/A conversion engine with your document

How to use

Download and install GdPicture.NET package from here.

You will find a compiled demo applications in
[Install directory]\Samples\Bin\

You will find C# and VB.NET demo applications including source code in
[Install directory]\Samples\WinForm\

You will find other code snippets within the online reference guide found here

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60 Days Free Trial Download GdPicture.NET Now!