Validate PDF conformance

PDF conformance validation verifies that a document actually complies with the archival (PDF/A) or accessibility (PDF/UA) standard it claims. A document that carries a PDF/A or PDF/UA identifier in its metadata isn’t guaranteed to satisfy the standard — files produced by external tools, edited after conversion, or assembled from mixed sources often violate the requirements they declare.

Conformance validation is a common requirement in these workflows:

• Archive ingestion — Verifying documents before accepting them into long-term storage
• Compliance auditing — Checking existing document repositories against declared standards
• Conversion verification — Confirming the output of a PDF/A or PDF/UA conversion pipeline
• Accessibility programs — Testing documents against PDF/UA before publication

This sample demonstrates how to validate a PDF document against the conformance level it claims, and how to force validation against a specific conformance level.

Validating documents with our Python SDK

Developers can implement this feature by adding a few lines of code to their applications. The SDK validates all PDF/A conformance levels (PDF/A-1 through PDF/A-4) and PDF/UA-1 with a single API, and it produces a detailed report that lists every rule violation it finds.

Preparing the project

Import Nutrient Python SDK:

from nutrient_sdk import Document
from nutrient_sdk import PdfValidator
from nutrient_sdk import PdfValidationConformance
from nutrient_sdk import NutrientException

Loading the PDF document

Use Python’s context manager(opens in a new tab) to enable proper lifecycle management of the document instance. The validator only accepts PDF documents; other formats aren’t converted implicitly:

def main():
    try:
        with Document.open("input_pdfa_valid.pdf") as document:

This path can be absolute or relative. This example loads the file from the application’s working directory.

Validating the claimed conformance

Create a validator instance bound to the document with PdfValidator.set(document), then call validate(). By default, the validator reads the conformance level the document claims in its metadata and validates against it:

            validator = PdfValidator.set(document)

            result = validator.validate()
            print(f"Document is valid: {result.is_valid}")
            print(f"Validated conformance: {result.validated_conformance}")

            with open("report.xml", "w", encoding="utf-8") as report_file:
                report_file.write(result.report)

The result carries three values:

• is_valid — Whether the document complies with the conformance level it was validated against.
• validated_conformance — The conformance level the validation ran against. In automatic mode, this is the level detected from the document’s metadata.
• report — A detailed machine-readable XML report. When the document doesn’t comply, the report lists every problem found during validation.

If the document claims no PDF/A or PDF/UA conformance at all, no validation runs: the result reports the document as not valid, validated_conformance stays at PdfValidationConformance.AUTO, and the report explains that there was nothing to validate against.

Forcing a specific conformance level

To check a document against a standard it doesn’t claim — for example, to test whether an archival document is also accessible — set the conformance property before calling validate():

            validator.conformance = PdfValidationConformance.PDF_UA1

            ua_result = validator.validate()
            print(f"PDF/UA-1 conformant: {ua_result.is_valid}")
    except NutrientException as e:
        print(f"Error: {e}")


if __name__ == "__main__":
    main()

The sample document is a valid PDF/A file, so the forced PDF/UA-1 check reports it as not conformant — the accessibility standard imposes tagging and structure requirements that archival conformance doesn’t.

The PdfValidationConformance enumeration covers all supported validation targets:

• PDF/A-1 — PDF_A1A, PDF_A1B
• PDF/A-2 — PDF_A2A, PDF_A2U, PDF_A2B
• PDF/A-3 — PDF_A3A, PDF_A3U, PDF_A3B
• PDF/A-4 — PDF_A4, PDF_A4E, PDF_A4F
• PDF/UA-1 — PDF_UA1
• Automatic — AUTO (validates against the claimed conformance; this is the default)

Error handling

Nutrient Python SDK handles errors with exception handling. The methods presented in this guide raise a NutrientException if a failure occurs — for example, when the document isn’t a PDF or when it’s encrypted. This helps with troubleshooting and implementing error handling logic.

Conclusion

That’s all it takes to verify that a PDF document genuinely complies with the archival or accessibility standard it claims. To produce compliant documents from regular PDF files, refer to the PDF to PDF/A and PDF to PDF/UA guides. You can also download this ready-to-use sample package, which is configured to help you explore the Python SDK and conformance validation capabilities.