Isaac Maw
Technical Content Creator
Updated February 12, 2026
7 min
Comparing Capabilities: Top C# PDF SDKs in 2026
Isaac Maw
Technical Content Creator
Summary: This post compares popular C# PDF SDKs and libraries used in frameworks like .NET. Check out the strengths and drawbacks of popular options before learning what sets Apryse apart for developers.
When you need to add PDF functionality to your C# application, these C# PDF libraries are probably on your list for evaluation. In this article, let’s take a look at the pros and cons of each of these C# PDF libraries to help you find the best solution.
What Do Developers Look For in a Document SDK?
Document processing requirements in many applications across industries such as legal, insurance, business and architecture, engineering and construction (AEC) go beyond simple PDFs. Support for other file types, such as DOCX, XLSX, images, and even CAD files help meet all the document needs of your application.
Most top document processing SDKs handle simple PDF creation and manipulation, essential PDF tools such as redaction and digital signatures, and complex features such as annotations, data extraction, and template generation.
When evaluating document SDK vendors for your .NET or other C# application, consider more than price and features. Extensibility and support for your documents end-to-end, as they complete an entire lifecycle through your users’ workflows, is critical to ensure you’re building the right foundation for future growth.
Important considerations for your C# document library include:
- Proven functionality: the ability to demo or preview the functionality using resources like sample code and videos helps ensure the solution will meet your needs out of the box.
- Performance and scalability: not all libraries are enterprise-grade. For example, just as workarounds and hacks don’t scale to production, some commercial SDKs won’t handle your use case, especially depending on concurrency, file size and document complexity.
- Licensing: different licensing and pricing models accommodate different use cases. For example, some commercial SDKs aren’t cost-effective at low usage, while other models scale costs rapidly with usage. Consider how your needs synergize with available licensing.
- Documentation: to get up and running fast and integrate the SDK into the application, extensive, clear documentation is valuable, especially when it includes Get Started Guides, sample code, and live support.
Comparing C# SDK Options
The information below is current as of February 2026.
Aspose
Aspose is a commercial suite of APIs and cloud-based tools for manipulating documents, including PDFs. Aspose is commonly used for document creation, manipulation, and conversion.
Strengths:
- Good conversion accuracy between formats
- Extensive documentation
- Broad file format support
Drawbacks:
- Some developers report a steep learning curve to get through the extensive documentation
- Issues handling large, complex documents
- Limited scope, lacking features such as PDF text editing, secure redaction, and form handling features
Nutrient
Formerly PSPDFKit, Nutrient is a commercial PDF SDK vendor. The Nutrient SDK is built on a fork of PDFium, an open-source PDF library developed by Google.
Strengths:
- Good for simple PDF-centric use cases, especially when rendering performance and speed is less important.
- Offers a web sandbox for developers to use for testing
Drawbacks:
- Closed-source UI with limited customization
- Being built on PDFium limits performance
IronPDF
IronSoftware offers IronPDF for rendering, editing, and manipulating PDFs and other document types in .NET and other C# frameworks.
Strengths:
- High quality HTML-to-PDF rendering, using a Chromium engine to render HTML, CSS, and JavaScript for PDF conversion
- Supports a range of PDF manipulation tools, such as split, merge, watermarks, and headers and footers
- Developers report that IronPDF is easy to integrate, with a variety of tutorials and resources for getting set up.
Drawbacks:
- Chromium increases IronPDF’s footprint, including deployment size and memory needs.
- Lacks functionality for complex documents, such as PDF/A and PDF/UA
Syncfusion
Syncfusion offers collections of libraries to create, edit, write, and convert PDF, Excel, Word, and PowerPoint file formats in C# and other languages.
Strengths:
- Offers a lot of libraries for different utilities and tools
- Basic plug-and-play functionality
- Includes DOCX and spreadsheet functionality
Drawbacks:
- While Apryse is built on a unified core SDK with a broad set of functionality built into one SDK, Syncfusion maintains multiple libraries. This could result in inconsistent capabilities, quality, and maintenance across libraries.
- Some Syncfusion components are restricted to either web applications or Microsoft applications, reducing flexibility.
- Apryse offers superior performance with complex documents and batch processing compared to Syncfusion.
- Being built on PDFium limits performance
PDFsharp + Migradoc
PDFSharp is an open-source C# library for processing PDF files, including creation, rendering, printing, manipulation (split, merge, modify pages) and extract text and metadata of PDF files.
Strengths:
- Supports a variety of basic PDF capabilities, including support for images, drawing shapes, and font embedding.
- Lightweight solution
Drawbacks:
- Lacks support for file formats beyond PDF and some image formats
- Limited performance with large and complex files
- Lacks built-in support for features like encryption, form filling, and redaction
QuestPDF
Focused on PDF generation, QuestPDF is a toolkit designed to support PDF functionality such as merging documents, manipulating pages, formatting, encrypting, and composing PDF documents. However, as a dedicated PDF generation library, it lacks the full suite of document processing capabilities that other SDKs (such as Apryse) offer.
Strengths:
- Minimal API, designed for developer ease of use
- Includes free-to-use licensing options for small projects
- Includes a companion app to help visualize or preview server-side document creation
Drawbacks:
- Lacks support for document processing capability beyond creation, such as:
- PDF Editing
- PDF Text Extraction
- Digital Signatures
- OCR
- Support for other formats besides PDF
- PDF viewing
- Poor performance for large documents
- Single-threaded document processing limits scalability
iText Core
iText Core by Apryse is a robust PDF toolkit which offers open-source and closed-source options. IText Core is a straightforward library designed to handle PDF creation.
Strengths:
- Customizable and extensible: The comprehensive Java and .NET (C#) PDF libraries have both out of the box functionality, for easy use, and the flexibility to extend and customize to meet your needs. iText Core focuses on easy integration and open standards.
- Feature-rich and enterprise-grade, supporting a wide range of PDF features and tool sets, for:
- PDF creation and manipulation
- Digital signatures
- OCR
- Redaction
- Document optimization
- Forms
- Robust, proprietary layout engine for precise rendering and page composition
- Supports easy creation of PDFs from HTML
Drawbacks:
- Compared to Apryse SDK, feature set is narrower, with less support for the full document lifecycle.
- Limited format support, primarily working with PDF, as well as HTML and XML conversion.
- Focused on code-driven and programmatic PDF generation, while Apryse supports end-to-end embeddable document workflows.
Apryse SDK
Apryse Server SDK is available for C# frameworks such as .NET, as well as other languages including .NET Core, C++, Javascript, Java, PHP, Go, Python and Ruby. It’s ready to drop into your existing .NET application and begin supporting your entire document lifecycle immediately.
A key difference between Apryse SDK and other SDK options is the comprehensive suite of document capabilities Apryse SDK offers, with high performance and high fidelity across the board, including:
- Template generation, conversion, viewing, editing, and signing of PDFs,
- Accessible DOCX and Spreadsheet editing
- Smart Data Extraction and OCR
- CAD capabilities, including rendering, measuring and comparing drawings
- Secure redaction, encryption and archiving with PDF/A and PDF/UA support
Apryse is built on proprietary technology developed and maintained in-house, with regular security and feature updates, providing better customization, reliability and innovation compared to SDKs built on open-source libraries like PDFium.
Apryse documentation and developer resources include step-by-step get started guides, videos, sample code for supported languages, a detailed API, and tailored support. Developers can start a free trial to test capabilities, or access the Showcase to try features instantly.
Getting Started with Apryse in C#
Using the Server SDK allows you to build server-side document processing solutions at scale without relying on client devices or cloud APIs. Since the Server runs entirely on-premises (or in your private cloud), you can ensure security and compliance with full control over access, storage, and encryption. You can also easily integrate with web apps, backend systems, document management systems, and content workflows.
The base package is robust, allowing you to programmatically do the following with PDFs:
If you’re looking for additional capabilities, we offer add-on packages, such as Smart Data Extraction, and add-on modules, such as Office Conversion.
Try the Apryse Server SDK in your C# application by following this video guide, or visit our documentation page to access the step-by-step instructions.
Next Steps
If you’re interested in evaluating the best document SDK for your specific use case, contact sales and chat with us directly.
You can also start your free trial and test your workflow, with an Apryse watermark.
Lastly, check out our sample code and repository to find additional resources.
Suggested Reads:
- https://apryse.com/blog/how-to-convert-jpeg-to-pdf-in-csharp-server-sdk
- https://apryse.com/blog/digitally-signing-pdfs-hardware-key-sdk-csharp-part-2
- https://apryse.com/blog/convert-txt-pdf-csharp-vb-java
- https://apryse.com/blog/how-to-build-a-c-sharp-pdf-viewer
- https://apryse.com/blog/conversion/pdf-to-office-conversion-with-csharp-and-net-core
- https://apryse.com/blog/merge-split-reorder-pdfs-csharp
