Which PDF Standard Is Better to Choose

For some tasks, certain PDF standards will fit better or vice versa worse. In this article, we will try to determine which PDF standards for which cases it makes sense to choose.

PDF 1.7 vs PDF 2.0

At the moment there is no big difference between Aspose.Words' PDF 1.7 and PDF 2.0 output.

Aspose.Words PDF 2.0 output just allows to use some new features, such as a new encryption algorithm. But there may be difficulties in handling of PDF 2.0 output in older PDF viewers. So, PDF 2.0 should be used if new features are needed. Otherwise, PDF 1.7 should be used.

This may be reconsidered later.

When to Use PDF/A and Which Version

PDF/A is a format for archiving and long-term preservation. Generally it is required by authorities, archives, libraries, and so on. So, the use of PDF/A compliance is dictated by the requirements of the PDF consumer. And if PDF consumers do not require it, then it should not be used.

The PDF/A version should be selected to be the highest acceptable for the consume, since higher versions are more reliable for Aspose.Words PDF/A output. However, the conformance level for PDF/A-1 or PDF/A-2 should also be selected according to consumer requirements. Thus, if level A is required, then it should be used, and if level B/U is required, then both level B/U and level A could be used.

Note that level A documents are accessible but take more space than level B/U documents.

When to Use PDF/UA

PDF/UA should be used if PDF consumers require it. Also it could be used if you just need the accessible PDF output, but it will take more space compared to regular PDF output.

FAQ

  1. Q: What is the practical difference between PDF 1.7 and PDF 2.0 when using Aspose.Words for C++?
    A: Functionally they are very similar; PDF 2.0 adds support for newer features such as an advanced encryption algorithm. Use PDF 2.0 only when you need those features, otherwise PDF 1.7 offers broader compatibility with older viewers.

  2. Q: When should I choose PDF/A over regular PDF output?
    A: Choose PDF/A when the document must be archived for long‑term preservation or when a regulatory body requires it. Select the highest PDF/A version (e.g., PDF/A‑2) that the consumer accepts, and pick the appropriate conformance level (A, B, or U) based on accessibility needs.

  3. Q: Does PDF/UA increase the file size compared to a normal PDF?
    A: Yes, PDF/UA adds extra metadata and structure to meet accessibility standards, which typically results in a larger file size than a non‑accessible PDF.

  4. Q: Can I use the new encryption algorithm available in PDF 2.0 with Aspose.Words for C++?
    A: Yes. When you generate a PDF 2.0 document you can enable the new encryption algorithm via the PdfSaveOptions class. Keep in mind that some older PDF readers may not support this algorithm.

  5. Q: Is there any impact on performance when generating PDF/A or PDF/UA documents?
    A: Generating PDF/A or PDF/UA may be slightly slower because Aspose.Words performs additional validation and adds required metadata. The impact is usually minimal, but it can be noticeable for very large documents.

Conversion to PDF/A and PDF/UA Working with PDF/A or PDF/UA