pdfio

PDFio - PDF Read/Write Library

PDFio is a simple C library for reading and writing PDF files. The primary goals of PDFio are:

• Read and write any version of PDF file
• Provide access to pages, objects, and streams within a PDF file
• Support reading and writing of encrypted PDF files
• Extract or embed useful metadata (author, creator, page information, etc.)
• “Filter” PDF files, for example to extract a range of pages or to embed fonts that are missing from a PDF
• Provide access to objects used for each page

PDFio is not concerned with rendering or viewing a PDF file, although a PDF RIP or viewer could be written using it.

Copyright © 2021-2026 by Michael R Sweet. PDFio is licensed under the Apache License Version 2.0 with an (optional) exception to allow linking against GNU GPL2-only software. See the files LICENSE and NOTICE for more information.

Reading the Documentation

Initial documentation to get you started is provided in the root directory of the PDFio sources:

• CHANGES.md: A list of changes for each release of PDFio.
• CODE_OF_CONDUCT.md: Code of conduct for the project.
• CONTRIBUTING.md: Guidelines for contributing to the project.
• INSTALL.md: Instructions for building, testing, and installing PDFio.
• LICENSE: The PDFio license agreement (Apache 2.0).
• NOTICE: Copyright notices and exceptions to the PDFio license agreement.
• README.md: This file.
• SECURITY.md: How (and when) to report security issues.

You will find the PDFio documentation in HTML, EPUB, and man formats in the doc directory.

Examples can be found in the examples directory.

Please read the documentation before asking questions.