Open Source PDF Libraries and Tools VS ComPDFKit

By ComPDFKit | 2023 Jun 14
Top List PDF SDK Open Source

Open-source PDF libraries are free and accessible to the public so that anyone can inspect, modify, and share the code. They are distributed under open-source licenses and offer some basic features like reading. Most developers seek the perfect open-source PDF editor for their platforms. So, we research and survey many open-source PDF libraries and introduce you top 8 PDF libraries here. Keep reading to discover the ideal solution for your needs.


Comparison Table

Reading through all the extensive details can be time-consuming. However, this comparison table provides a clear presentation of the specific points that matter to you.



Stirling PDF

Stirling PDF is a powerful, locally hosted, web-based, Docker-powered PDF manipulation platform. Originally powered by ChatGPT, it has since evolved to provide a comprehensive set of features. It allows you to perform basic tasks like merging and splitting PDFs, as well as more advanced operations like compression, OCR, and conversions. Many complicated PDF features are freely available and perform great after our test of deploying Stirling PDF with Docker. When taking an example of PDF conversion, Stirling PDF does have the OCR parameter which is really useful for converting and extracting scanned PDFs. However, integrating this OCR feature requires extra configuration and may take additional time for developers, with no detailed guides available for assistance.




- Free

- Extensive range of PDF functionalities that most commercial products provide

- Customizable UI and PDF security are supported

- The performance meets most of the requirements for editing PDF files



- No comprehensive documentation to guide developers

- Need extra configuration when needing advanced features

- Only support Web application development

- No detailed documentation and technical support




MuPDF is an open-source software framework for viewing and converting PDF, XPS, and eBook documents. It supports a wide range of coding environments and operating systems, including Windows, Linux, Android, iOS, Java, Webassembly, C, C++, etc. MuPDF can be used for a variety of embedded, host-based, mobile, or cloud applications. Unfortunately, MuPDF's App Kit has been discontinued, which has prompted developers to eagerly search for the best MuPDF alternatives.




- Free

- Minimum 2MB

- A great variety of features

- Multiple platform compatibility

- Support desktop, cloud/server, and core API



- Suddenly stop maintenance without notifying

- Lack of guarantee of continued service

- Doesn't work well for sometime



If your requirements extend beyond the capabilities of open-source PDF libraries and demand broader platform compatibility along with comprehensive PDF functionalities, consider leveraging ComPDFKit. We offer a 30-day free trial license that seamlessly integrates with all major platforms, supporting development on Windows, Mac, Linux, Web, Android, iOS, Flutter, React Native, Electron, and more. Whether you prefer deploying our local PDF SDK, utilizing our online API, or setting up self-hosted servers, we cater to your specific needs.


In addition to clear and extensive documentation, our dedicated R&D team is readily available to assist you, even during the trial period. ComPDFKit's PDF SDK undergoes continuous optimization and updates in iterations, with a focus on enhancing user experience and ensuring client satisfaction.




- Comprehensive PDF features

- Support multiple platforms and various languages

- Provide full deployment options

- Elaborated and understandable development documentation

- Continuous optimization and updates in iterations

- Instant technical support via any required ways

- Offer a 30-day free trial license without any requirement

- Free to process 1000 PDF files per month using our PDF API with no limitations



- It’s not free



PDF.js is an open-source JavaScript library designed to seamlessly render and display PDF documents directly within web browsers without the need for additional plugins or external dependencies. Developed by Mozilla, PDF.js empowers web developers to integrate efficient and customizable PDF viewing experiences into their web applications. However, PDF.js only has support for basic PDF functions and there exist issues with the render fidelity of PDF.js. However, PDF.js only supports basic PDF functionality and there are issues with its rendering fidelity.




- Free

- Customizable UI and common PDF functions

- Process PDF files on any browser



- Large or complex files easily result in performance issues

- Lack of advanced or dedicated PDF viewers or libraries

- Only support for Web application development


LibreOffice Draw PDF Editor

LibreOffice is an open-source integrated office suite, which is compatible with most document formats and standards. It is available on many mainstream operating systems like Windows, MacOS, and Linux. One of its key applications called Draw serves as the default PDF editing application. This feature-rich tool supports tasks such as adding text, images, shapes, and annotations, making it a valuable resource for both basic and advanced PDF editing needs. LibreOffice Draw stands out as an accessible and cost-effective solution for users seeking powerful PDF editing capabilities.




- Free

- Various PDF features satisfy fundamental needs

- Draw seamlessly integrates with other LibreOffice applications



- Does not have a user-friendly interface

- Has confusing menu options

- Limited advanced features

- Large files might lead to performance issues


PDFSam Basic

PDFSam Basic is a free and open-source PDF editor for splitting, merging, rotating, mixing, and extracting pages from PDF files. It supports many platforms including Windows, Linux, and MacOS. It requires approximately 70 MB of disk space, 256 MB of RAM, and a 64-bit operating system. Aside from PDFSam Basic, they also provide two commercial solutions- PDFsam Enhanced and PDFsam Visual. Professional users can choose any of them with advanced features.




- Free

- Support multiple languages

- Support basic PDF document editing functions



- A bit difficult to learn for beginners

- No advanced functionalities for editing PDFs

- No support for mobile app development

- No technical support or guarantee of iteration.


Apache OpenOffice Draw

Apache OpenOffice Draw is highly regarded for its exceptional quality and versatility. It functions seamlessly as both a PDF reader and an open-source PDF editor, offering a user-friendly experience. Packed with a range of features, it allows for easy customization of PDF pages, diverse file format saving, and effortless text editing with options for removal or insertion. Additionally, users can benefit from convenient import and export functions and spell-checking capabilities for PDF files. The best part is, it's completely free to use and supports various operating systems, including Windows, Mac, and Linux, ensuring accessibility and a pleasant user experience.



- Free

- Easy to learn

- Apache OpenOffice Draw seamlessly integrates with other applications in the suite



- The user interface is less modern and attractive

- Lack of some advanced features, limiting its suitability for complex design projects

- Performance issues might occur when handling large and complex files

- Updates and new features may be infrequent



Preview, available solely on the macOS platform, is an open-source PDF editor primarily designed by Apple for viewing images and PDFs. Its functionalities extend beyond basic markup and annotation tools, encompassing more advanced features. Users can leverage Preview to encrypt and sign PDFs, extract specific pages, manipulate page content, fill out forms, and access other professional-grade capabilities.




- Free

- Meet general needs for editing PDFs

- No installation troubles



- Only support Mac

- No support for OCR



ComPDFKit stands out as a more professional choice among open-source PDF editors, offering unique advantages. With platform flexibility, it provides dedicated SDKs for development on any platform. The incorporation of all features into a single SDK eliminates the need to add various functionalities from different SDKs, preventing redundant development efforts. This streamlines the development process, delivering a more efficient and comprehensive solution.


The Bottom Line

By comparing these open-source PDF editors, you have understood their respective advantages and disadvantages, and can clearly determine which one better meets your needs. If you have higher performance requirements and want more advanced features, it is highly recommended try ComPDFKit PDF SDK with a 30-day free trial. If you want to know the performance, advantages, and disadvantages of other open-source PDF libraries, welcome to contact us and we will test them again and update this post.