You have a PDF document and must convert it to PDF/A, but you are not sure how to do it or which version to choose? If so, we are here to guide you through converting your PDF to a PDF/A file.
In this article, learn about different PDF/A versions, conformance levels, and how to convert your document to your preferred PDF/A format.
Which PDF/A Version and Conformance Level to Select
Before you convert files to PDF/A, the conversion tool will ask you to choose a PDF/A standard (PDF/A-1, PDF/A-2, PDF/A-3) and a conformance level (a, b & u). They may seem similar at first, but your choice can affect the conversion process and whether additional changes are required.
Knowing the PDF/A versions and conformance levels helps you choose the right option for your documents, based on how you plan to use them.
When you convert a typical PDF file to the original PDF/A-1 standard, it usually requires the most changes. For example, the file may become larger because it cannot use newer image compression technologies.
PDF/A-1 specifies two levels of conformance:
- PDF/A-1b - Level B (basic) conformance. Mandatory requirements include embedded fonts, color management information, and metadata. PDF/A-1b is mostly used to archive scanned documents or existing PDF files.
- PDF/A-1a - Level A (accessible) conformance.
Additional Level A requirements:
- Language specification,
- Hierarchical document structure,
- Tagged text spans and descriptive text for images and symbols,
- Character mappings to Unicode.
A PDF/A-1a file is easier to navigate, its content is easier to reuse, and it is easier to read for visually impaired people. The text is usually better in terms of reproducibility. Unlike basic conformance, accessible conformance allows the user to search the document for a keyword.
PDF/A-2, in comparison, requires fewer changes, since it allows JPEG 2000 compression, transparent elements, and PDF layers. As a result, your files will usually be smaller. There are 3 different PDF/A-2 types: PDF/A-2a, PDF/A-2u, and PDF/A-2b.
As mentioned, part 2 of the standard offers some additional features:
- JPEG 2000 image compression
- Support for transparency effects and layers
- Embedding of OpenType fonts
- Support for digital signatures in accordance with PDF Advanced Electronic Signatures
- The option to embed PDF/A files to archive sets of documents in a single file
PDF/A-2a and PDF/A-2b correspond to conformance levels a and b in PDF/A-1. PDF/A-2u, however, represents Level B conformance (PDF/A-2b) with the additional requirement that all text in the document has Unicode mapping.
PDF/A-3 is practically the same as PDF/A-2, but it also allows embedding non-PDF/A files. If you plan to use or process many files with non-PDF/A attachments, PDF/A-3 can be a suitable option. This format can be seen as a "complete" one, since PDF/A itself keeps scanned documents readable in the long term, MRC compression keeps file size small, OCR makes it searchable, and attachments support document exchange. Choose the format that best fits your archiving needs.
Basics of conformance levels in brief:
- Level B (Basic) conformance is the easiest level to achieve. It only requires that documents follow guidelines for reliable viewing. The document will look the same when it is viewed or printed, even in the long term.
- Level A (Accessible) conformance includes all Level B requirements plus features that improve a document's accessibility. It enables text that can be reliably searched and copied, and content that is more accessible to technologies like screen readers for visually impaired users.
- Level U (Unicode) conformance was introduced with PDF/A-2. It guarantees that document text can be mapped to standard Unicode character codes.
How to convert your PDF to PDF/A?
PDF to PDF/A conversion tool can be used to efficiently convert your PDF document to its standardized ISO version. There is no need to download and install new programs on your computer. Our PDF/A converter enables you to convert PDF to PDF/A conveniently online. Follow these steps below:
- Click "Choose File" to select a PDF file to upload. You can also drag and drop the PDF file. Uploading a file from the Internet (Enter URL) or from cloud storage services (Google Drive, Dropbox) is also possible.
- Choose the PDF/A format you would like to convert to: PDF/A-1b, PDF/A-2b, or PDF/A-3b.
- Optional setting - Enable strict mode to access all conformance levels (a, b & u).
- Click Start to begin the conversion.
- Download your new PDF/A file.
Worth considering: While higher conformance levels (a or u) can increase the value of your documents, they can also be more time-consuming. By selecting Level B conformance, such as PDF/A-2b, your documents will follow the guidelines for reliable viewing without extra requirements, saving you time.
Is PDF/A searchable?
Yes, it is! PDF/A allows text recognition processes, which is one of its main benefits. The text of digitally generated content is preserved in the document, including text extracted with optical character recognition (OCR), so even scanned PDF/A documents can be searched.
What does "PDF/A compliant" mean?
PDF/A compliant simply means that your file meets the requirements of the PDF/A format. Some PDF/A conformance requirements include:
- All content is embedded (fonts, colors, text, images, etc.)
- Audio and video content is prohibited.
- The file is not encrypted.
- The file does not contain references to external content.
- The file uses standards-based metadata.
- Interactive PDF form fields must have an appearance dictionary.
- The file does not contain JavaScript.
What about validation? Is it necessary?
Since it is not always easy to tell whether an existing PDF file actually meets the ISO PDF/A standard, it is recommended to run a validation check that examines all relevant parts of your document.
How to validate PDF/A files
PDF/A validators can be used to confirm that a file is actually a PDF/A file. These are online tools that verify if all elements of the standard have been met. PDF/A files created with our online converter are ISO-compliant and pass Vera PDF validation. Vera PDF is an open-source file-format validator that covers all PDF/A parts and conformance levels.
