How to Validate PDF/A Conformance with cURL

Learn how to use Query PDF API Tool by pdfRest with cURL to validate PDF/A conformance
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Why Validate PDF/A with cURL?

The pdfRest Query PDF API Tool provides a convenient way to extract specific information from PDF files programmatically. With this tool, you can retrieve metadata such as the title, page count, document language, and author of a PDF. This tutorial will show how to send an API call to Query PDF using cURL, a powerful and versatile command-line tool used for transferring data with URLs. It's a popular choice for interacting with web APIs due to its ubiquity and flexibility.

PDF/A conformance validation offers a powerful solution for seamless collaboration. By validating your PDFs as PDF/A, you're creating universally compatible documents that can be reliably opened, viewed, and processed by any recipient, regardless of their software or operating system. This eliminates compatibility issues that can hinder workflows and communication. Additionally, PDF/A validation ensures the integrity of the document's content and embedded metadata, fostering trust and data accuracy during collaboration. For businesses that rely on external partners or share documents frequently, PDF/A validation streamlines document exchange and fosters smooth collaboration across teams.

Validate PDF/A with cURL Code Example

curl -X POST "" \
  -H "Accept: application/json" \
  -H "Content-Type: multipart/form-data" \
  -H "Api-Key: xxxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" \
  -F "file=@/path/to/file" \
  -F "queries=pdfa"

The provided code is sourced from the pdf-rest-api-samples repository on GitHub.

Breaking Down the Code

The cURL command provided is used to make a POST request to the pdfRest API endpoint for querying PDF information. Let's break down the command:


This specifies the HTTP method for the request, which is POST in this case, indicating that data will be sent to the server.


This is the URL of the API endpoint that will process the request to retrieve information from a PDF.

-H "Accept: application/json"

This header tells the server that the client expects a response in JSON format.

-H "Content-Type: multipart/form-data"

This header indicates that the data being sent in the request is in multipart/form-data format, which is commonly used for file uploads.

-H "Api-Key: xxxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"

This header provides the API key required for authentication with the pdfRest service. The 'xxxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx' should be replaced with your actual API key.

-F "file=@/path/to/file"

The -F flag is used to specify each field that will be sent as part of the multipart/form-data request. Here, it indicates the file to be uploaded, with '@/path/to/file' being the local path to the PDF file you want to query.

-F "queries=pdfa"

This field specifies the pieces of information you want to query from the PDF file. The API will return the results of a PDF/A validation check with a simple true or false response.

Beyond the Tutorial

In this tutorial, we learned how to use cURL to make a multipart/form-data POST request to the pdfRest API to query information from a PDF file. By sending this request, we can programmatically validate whether a PDF/A is conformant, allowing for conditional processing based on the result.

To explore and demo all of the pdfRest API Tools, visit the API Lab. For more detailed information on the API and its capabilities, refer to the API Reference Guide.

Note: This is an example of a multipart API call. Code samples using JSON payloads can be found at the pdf-rest-api-samples repository on GitHub.

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