C# is a powerful programming language, widely used for software development across various domains. One crucial aspect of application development is dealing with PDFs, whether generating PDFs, extracting information from existing PDF documents, or manipulating PDF files.
In this article, we'll explore eight C# PDF-generating libraries that every developer might use at some point. We'll explore each of the hand-picked library options, with a special focus on IronPDF, a comprehensive PDF solution.
Table of Contents
Introduction to C# PDF Libraries
IronPDF - Your Comprehensive PDF Solution
PdfSharp
iTextSharp
Pdfium
Syncfusion PDF
Aspose.PDF
Spire.PDF
QuestPDF
Conclusion: The Best C# PDF Library For You (2024)
1. Introduction to C# PDF Libraries
C# developers often encounter the need to work with PDFs (Portable Document Format) due to their widespread use in document management. PDF libraries play a vital role in simplifying tasks related to PDF generation, manipulation, extraction and to even convert PDF documents to different format.
During the review, we paid special attention to the following aspects of PDF libraries:
Ease of use
Performance
Quality and availability of support
Price
Licensing terms
2. IronPDF - Your Comprehensive PDF Solution
IronPDF stands out as a comprehensive and versatile C# .NET PDF library designed to elevate your PDF file management experience. With a user-friendly API, IronPDF prioritizes accuracy, ease of use, and cross-platform support. It is available for all .NET Framework versions, making it a first choice when it comes to C# application development with PDF generation capabilities. You can download the software directly from here.
With well-documented example code pages, IronPDF eliminates the learning curve, enabling developers to kickstart their PDF-related tasks effortlessly. The given code examples are usually just a few lines to perform PDF operations, making it simple and easy to integrate without knowing its complexities. Whether you are a seasoned developer or a newcomer, the intuitive API and detailed documentation streamline the integration process, ensuring that you can quickly grasp the library's functionality.
HTML to PDF Conversion: Chromium-based rendering ensures 99% accuracy
Here's a quick example code on how to generate PDF documents from HTML string, files, and URL in C# using IronPDF:
using IronPdf;
// Instantiate Renderer
var renderer = new ChromePdfRenderer();
// Create a PDF from an existing HTML file using C#
var htmlFile_to_pdf = renderer.RenderHtmlFileAsPdf("example.html");
// Create a PDF from a HTML string using C#
var htmlString_to_pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");
// Create a PDF from a URL or local file path
var url_to_pdf = renderer.RenderUrlAsPdf("https://ironpdf.com/");
// Export to a file or Stream
htmlFile_to_pdf.SaveAs("htmlFile.pdf");
url_to_pdf.SaveAs("url.pdf");
htmlString_to_pdf.SaveAs("htmlString.pdf");
Features
Let's take a dig at the complexities of IronPDF and explore its standout features that position it as a vital C# .NET library for developers working on a wide array of PDF operations like the ability to modify PDF files or generate PDF documents from HTML.
Ease of Use: IronPDF provides a simple and intuitive API for common PDF operations, streamlining the workflow for developers.
Powerful Features: IronPDF supports a comprehensive set of PDF features. Whether it's to create PDF documents, manipulate PDF files and PDF forms, encrypt/decrypt, or apply digital signatures, IronPDF covers all. It also helps to convert HTML to PDF documents with page customizing options.
Performance: IronPDF is highly optimized, delivering efficient PDF generation and manipulation speeds, ensuring optimal user experiences.
Cross-Platform Compatibility: IronPDF is compatible with various operating systems and environments, including Windows, Linux, Mac, iOS, Android, Docker, Azure, and AWS.
Integration: IronPDF seamlessly integrates with popular IDEs like Microsoft Visual Studio and other .NET libraries, enhancing its appeal for developers working within established ecosystems.
Use Cases
Versatile PDF Operations: IronPDF is suitable for a wide array of PDF operations, from basic document creation to advanced features like encryption and digital signatures.
Cross-Platform Development: Developers working on diverse platforms, including web, mobile, desktop, or console applications, can seamlessly integrate IronPDF into their projects.
Performance-Critical Applications: IronPDF's optimized performance makes it suitable for applications where speed is crucial.
Security Features: IronPDF includes built-in encryption, password protection, and digital signing, adding an extra layer of security to your PDF documents.
When to Choose IronPDF?
Choose IronPDF if:
You require a comprehensive and powerful PDF solution with advanced features.
You value ease of use with an intuitive API.
You need cross-platform compatibility for diverse environments.
You want performance, with efficient PDF generation and manipulation speeds.
You work with complex projects demanding features like encryption, digital signatures, and versatile PDF operations.
You prefer seamless integration with popular IDEs and .NET libraries.
Support and Refund Policy
IronPDF provides a 30-day money-back guarantee and one year of support and updates with options for extended coverage. It offers different support levels tailored to users' needs and includes benefits like hotfixes and direct access to senior support during standard operating hours. Users can also provide feedback, report bugs, and request features to enhance the product.
Licensing and Cost Efficiency
IronPDF offers an affordable pricing model starting at $749, making it a great choice for startups and small teams. The library includes a 30-day free trial with full access to its features, allowing users to evaluate its capabilities before purchase. Additionally, the Royalty-free Redistribution option for $1,999 makes it suitable for broader application deployment, ensuring excellent cost efficiency for long-term use.
3. PdfSharp
PdfSharp is an open-source PDF library for C# that has gained popularity for its simplicity and ease of use. It provides developers with the tools to create and manipulate PDF documents effortlessly. PdfSharp is an excellent choice for projects where a straightforward and lightweight PDF solution is needed.
Features
Simplicity: PdfSharp is known for its simple and easy-to-use API, making it accessible for developers of all levels.
Ease of Use: Developers can quickly generate and manipulate PDFs with PdfSharp's intuitive interface.
Cross-Platform Support: Limited cross-platform support; primarily designed for Windows.
Performance: Generally lightweight and suitable for basic tasks; may have performance limitations for complex operations.
Use Cases
Simple Document Generation: PdfSharp is ideal for scenarios where basic PDF creation is required without complex features.
Educational Projects: Developers working on educational or learning applications can benefit from PdfSharp's simplicity.
When to Choose PdfSharp?
Choose PdfSharp if:
You prioritize simplicity and ease of use.
Your project requires basic PDF generation and manipulation.
Support and Refund Policy:
PDFsharp and MigraDoc Foundation are published under the MIT License, allowing free use, modification, and integration without restrictions, including in commercial products. Professional support is available for those who require additional assistance. However, when using free and open-source libraries, developers should be aware that there can be security threats and vulnerabilities.
Licensing and Cost Efficiency
PdfSharp is available under the open-source MIT License, making it free for both personal and commercial use. Since it is open-source, PdfSharp is an excellent choice for developers who need a cost-effective solution without licensing fees. However, it has fewer features compared to paid libraries.
4. iTextSharp
iTextSharp now known as iText Core, is a comprehensive Java and .NET library renowned for its robust capabilities in creating, manipulating, and extracting content from PDF documents. While it offers extensive functionality, including support for digital signatures, PDF security, and redaction, iText is often criticized for its low-level access and complex API, making it challenging to use compared to alternatives like IronPDF.
The library provides both open-source core functionality and paid extensions, allowing users to customize their solutions according to their specific requirements. Despite its steep learning curve and verbose code examples, iText remains a popular choice for developers seeking advanced PDF manipulation features and flexibility in document workflows.
Features
PDF Manipulation: iTextSharp excels in advanced PDF manipulation, allowing developers to create complex documents.
Versatility: It supports a wide range of PDF-related tasks, from document creation to text extraction.
Cross-Platform Support: Supports various platforms, including Windows, Linux, and macOS.
Performance: Known for good performance, especially in handling complex PDF operations.
-
HTML to PDF: While iText Core can handle HTML to PDF conversion, it doesn't offer the same level of accuracy and optimization as Chromium-based libraries like IronPDF.
- iText struggles with complex HTML layouts, which might lead to discrepancies in output when converting highly formatted HTML content to PDF.
Use Cases
Complex Document Generation: iTextSharp is the go-to choice for projects requiring intricate PDF layouts and structures.
Data Extraction: Developers dealing with data extraction from PDFs can benefit from iTextSharp's capabilities.
When to Choose iTextSharp?
Choose iTextSharp if:
Your project requires advanced PDF features and manipulation.
You are comfortable with both open-source and commercial licensing options.
Support and Refund Policy
iText offers a limited 90-day warranty with the option of a refund of license fees paid during the preceding three months, subject to certain conditions, and provides professional support through a paid support agreement with access to updates and direct assistance from in-house developers.
Licensing and Cost Efficiency
iTextSharp offers both open-source (GPL) and commercial licenses. The commercial license is priced higher, especially for enterprises requiring advanced features. The open-source version is more affordable for small or non-commercial projects.
iTextSharp’s open-source core is cost-efficient for small projects, but the commercial license can be expensive for larger applications. It’s a solid choice for enterprises requiring advanced PDF manipulation.
5. Pdfium
Pdfium is not a traditional PDF library but rather a PDF rendering engine with C# bindings. It allows developers to render PDFs and extract text or images from them. While Pdfium is more focused on rendering, it serves as a valuable tool for projects with specific rendering needs.
Features
PDF Rendering: Pdfium excels in rendering PDFs accurately, making it suitable for applications where visual fidelity is crucial.
Text and Image Extraction: Developers can extract text and images from PDF documents using Pdfium.
Cross-Platform Support: Offers cross-platform support; can be used in Windows, Linux, and macOS applications.
Performance: Primarily focused on rendering, providing good performance for visual-intensive applications.
Use Cases
Visual Intensive Applications: Pdfium is ideal for applications where the accurate rendering of PDFs is a priority.
Text or Image Extraction Projects: Developers focusing on extracting specific content from PDFs can leverage Pdfium.
When to Choose Pdfium?
Choose Pdfium if:
Your project requires precise PDF rendering.
You need to extract text or images from PDF documents.
Support and Refund Policy
PDFium.NET SDK Software License Agreement does not mention a specific return policy, and while basic technical support is not included, additional support services can be ordered separately for an additional charge.
Licensing and Cost Efficiency
Pdfium is released under the Apache 2.0 License, which is also open-source and free for both personal and commercial use. Pdfium is a great option for developers who need a free and open-source PDF rendering library. Its licensing makes it easy to integrate without any financial burden, though it lacks advanced PDF creation and manipulation features.
6. Syncfusion PDF
Syncfusion provides a robust PDF library for C# that stands out for its extensive feature set and flexibility. Syncfusion's PDF library enables developers to create, modify, and extract content from PDF documents seamlessly.
Features
Rich Feature Set: Syncfusion PDF offers a comprehensive set of features, including PDF creation, manipulation, and text extraction.
Flexibility: Developers can customize PDF documents with ease, thanks to Syncfusion's flexible API.
Cross-Platform Support: Provides cross-platform support, allowing developers to target Windows, Linux, and macOS.
Performance: Known for good performance, especially for extensive PDF operations and customization.
Web-Based Focus: Syncfusion PDF is not specifically optimized for web-to-PDF workflows, but it supports a wide range of PDF manipulation and customization tasks that can be integrated into web-based applications.
Rendering Engine: Syncfusion's proprietary rendering engine is highly capable, though it lacks the precision and pixel-perfect output of some other libraries like IronPDF.
Use Cases
Extensive PDF Operations: Syncfusion is suitable for projects requiring a broad range of PDF-related tasks.
Customization: Developers who need to create highly customized PDF documents will find Syncfusion's flexibility valuable.
When to Choose Syncfusion PDF?
Choose Syncfusion PDF if:
You need an extensive feature set for PDF operations.
Your project requires a high level of customization in PDF document creation.
Cross-platform support is essential for your application.
Support and Refund Policy
Syncfusion offers a 30-day money-back guarantee and 24-hour support, including online support, bug and feature requests, and access to remote support for team licenses, alongside an active community forum, knowledge base, and reliable service guaranteed by SLA.
Licensing and Cost Efficiency
Syncfusion PDF offers commercial licenses that are priced higher, particularly for enterprises requiring a broad set of features. These licenses provide excellent value for larger organizations, as the library is well-suited for extensive PDF operations and high levels of customization. While the pricing may seem higher for smaller projects, Syncfusion's robust feature set and flexibility make it an ideal choice for enterprise-level applications. For organizations needing complex PDF workflows, the investment in Syncfusion ensures a good return, given the library's comprehensive capabilities.
7. Aspose.PDF
Aspose.PDF offers a comprehensive solution for C# developers seeking powerful PDF manipulation capabilities. With its rich feature set and intuitive API, Aspose.PDF empowers developers to effortlessly create, edit, and extract content from PDF documents.
Features
Advanced Functionality: Aspose.PDF provides an extensive array of features, including PDF creation, manipulation, and extraction, along with support for various elements like text, images, and forms.
Intuitive API: With its user-friendly API design, developers can seamlessly integrate PDF functionalities into their applications with minimal effort.
Cross-Platform Compatibility: Aspose.PDF ensures compatibility across multiple platforms, enabling developers to target Windows, Linux, and macOS environments effortlessly.
Optimized Performance: Renowned for its performance optimization, Aspose.PDF delivers efficient handling of PDF operations, ensuring smooth execution even for complex tasks.
Advanced Security Features: Aspose.PDF includes security features such as encryption, password protection, and watermarking to help safeguard PDF documents.
Page and Content Customization: Aspose.PDF offers extensive features for customizing pages and document content, including font embedding, form filling, and text extraction capabilities.
Use Cases
Versatile PDF Operations: Aspose.PDF caters to diverse project requirements, offering a broad spectrum of PDF-related functionalities for tasks ranging from basic document creation to advanced manipulation.
Streamlined Customization: Developers seeking tailored PDF solutions benefit from Aspose.PDF's flexibility, enabling them to customize documents according to specific project needs with ease.
When to Choose Aspose.PDF?
Choose Aspose.PDF if:
You require a robust set of features for comprehensive PDF operations.
Your project demands seamless integration of PDF functionalities with minimal coding complexities.
Cross-platform compatibility is a crucial factor for your application's deployment.
Support and Refund Policy
Aspose.PDF provides both free and paid support options, with paid support offering prioritized issue resolution and escalation, ensuring faster resolution of critical issues from the outset. Additionally, a comprehensive refund policy allows requests within 15 days of purchase, subject to special considerations and applicable fees.
Licensing and Cost Efficiency
Aspose.PDF offers various licensing options, including subscription and perpetual licenses. These licenses are priced based on the type of deployment and the number of developers using the library. While Aspose.PDF's licensing costs may be higher compared to some alternatives, it offers extensive features that justify the price for large-scale, enterprise-level projects. Additionally, Aspose provides comprehensive support with the option for extended updates and priority service.
8. Spire.PDF
Spire.PDF for .NET stands as a versatile PDF API designed for seamless PDF creation, editing, and manipulation within .NET applications, including C#, VB.NET, ASP.NET, and more. This comprehensive library enables developers to handle PDF files without relying on external dependencies like Adobe Acrobat, fostering efficient document processing entirely through .NET platforms.
Features:
Digital Signature Support: Spire.PDF facilitates the addition and verification of digital signatures, ensuring document authenticity and integrity.
Text/Image Extraction: Extract text, images, and other content from PDF files with precision, enabling data retrieval and analysis.
PDF Merge/Split Operations: Seamlessly merge or split PDF documents to streamline content management and distribution.
Metadata Manipulation: Manipulate document metadata, including custom information, document properties, page orientation, and size, to meet specific requirements.
Data Conversion Capabilities: Spire.PDF supports extensive data conversion, allowing developers to convert text, images, SVG, and HTML to PDF, and vice versa, with high fidelity.
Use Cases
Document Customization: Customize PDF documents by adding digital signatures, protecting document integrity, and setting document properties.
Data Extraction: Extract data from PDF files, including text, images, pages, and attachments, for further analysis or processing.
PDF Conversion: Convert various file formats, such as HTML, SVG, XPS, images, and Office documents, to PDF format with efficient performance and high quality.
When to Choose Spire.PDF?
Choose Spire.PDF if:
When you require a comprehensive PDF solution with robust features for document manipulation and conversion.
If you prefer seamless integration into .NET applications without external dependencies like Adobe Acrobat.
When efficiency and accuracy in document processing are paramount for your project requirements.
Support and Refund Policy:
Spire.PDF offers prompt support via forums, email, and Skype, with a 30-day trial and a 14-day money-back guarantee. Refunds are granted for unresolved issues or delayed responses within 36 hours on weekdays. To request a refund, email the support team with your order details.
Licensing and Cost Efficiency
Spire.PDF offers both a free version with limited functionality and a paid version for advanced features. The commercial license is available for specific use cases like enterprise-level applications. The free version of Spire.PDF can be a good fit for small projects, but the paid version is necessary for large-scale applications requiring additional features like watermarking, digital signatures, and advanced PDF editing.
9. QuestPDF
QuestPDF is an open-source PDF library for C# that emphasizes simplicity and flexibility with a declarative, fluent API. It allows developers to create complex PDF documents with dynamic content and intricate layouts effortlessly.
Features
Fluent API: QuestPDF offers a fluent, chainable API that simplifies the process of defining the structure and content of PDF documents.
Declarative Layouts: Supports a declarative approach to document design, allowing you to specify the desired layout without worrying about manual measurements or positioning.
Cross-Platform Compatibility: Works seamlessly across different platforms, including Windows, Linux, and macOS.
Performance: Optimized for performance, ensuring fast and efficient PDF generation, even for documents with complex layouts or large data sets.
Use Cases
Dynamic Content Creation: Ideal for generating dynamic PDFs where the content can grow or shrink based on data, such as invoices, reports, or catalogs.
Custom Layouts: Suited for developers needing to create PDFs with highly customized layouts and styles.
When to Choose QuestPDF?
Choose QuestPDF if:
You prefer a fluent and declarative approach to defining PDF content.
Your project requires dynamic content generation and custom layouts.
Cross-platform support is necessary for your application.
Support and Community
QuestPDF is backed by an active community of developers and contributors. Although it is an open-source project without a formal support plan, it has extensive documentation, a dedicated GitHub repository for issue tracking and feature requests, and an engaged community forum for peer support. Remember, developers should be aware that security risks can arise when using an open-source project.
Licensing and Cost Efficiency
QuestPDF is open-source and available under the MIT License, offering free usage for personal and commercial projects with less than 1 million USD annual gross revenue. There is also a viable paid license available for Professionals with at most 10 developers and an Enterprise for unlimited developers. With its open-source license, QuestPDF is a cost-effective option for creating PDF documents. It’s a great choice for developers who don’t require extensive PDF manipulation features but need a straightforward solution for document generation.
10. Conclusion: The Best C# PDF Library For You (2025)
When trying to determine the best PDF library for your project in 2025, there are several key criteria you should be examining:
- How accurate is the outcome?
- How fast can you generate or render a PDF?
- How well does the library integrate with modern tools, frameworks, and AI systems?
- What is the quality and availability of documentation and tutorials?
- How responsive and helpful is the customer support or community?
- How frequently is the library updated and maintained?
Based on the latest updates, adoption trends, and developer feedback, our choices for 2025 are:
1. IronPDF
Latest Version: 2025.8.8 (August 2025)
Key Updates: IronPDF maintains its position as a leading commercial PDF solution with robust cross-platform support for .NET 9, 8, 7, 6, Core, Standard, and Framework. The library excels in HTML-to-PDF conversion with pixel-perfect rendering accuracy, leveraging a Chromium-based engine for exceptional CSS and JavaScript support.
2025 Enhancements:
- Expanded Platform Support: Now fully compatible with Windows (x64, x86), Mac (x64, ARM), and Linux (x64) environments
- Cloud Optimization: Enhanced deployment options for Docker, Azure (VPS, WebApp, Function), and AWS (EC2, Lambda)
- Development Experience: Improved integration with Microsoft Visual Studio and JetBrains Rider
Licensing: Offers a 30-day free trial with production licensing starting at $749.
Best For: Organizations requiring accurate HTML-to-PDF conversion with minimal configuration and enterprise-grade support.
2. PdfSharp (Including MigraDoc)
Latest Version: 6.2.1 (July 2025)
Key Updates: PdfSharp remains a popular open-source option for basic PDF generation, with recent updates focusing on .NET 6/8 compatibility and improved SVG rendering. The complementary MigraDoc library provides document generation capabilities with support for paragraphs, tables, charts, and sections, rendering to both PDF and RTF formats.
2025 Status:
- Maintenance Mode: The core library receives periodic updates but lacks the rapid feature development of commercial alternatives
- Community Activity: Active forks like PDFsharpCore enhance cross-platform support for Linux and Mac environments
- Licensing: Remains AGPL with commercial options available
Best For: Basic PDF creation and manipulation where licensing cost is a primary concern and advanced features are unnecessary.
3. iTextSharp (Now iText 9)
Latest Version: 9.2.0 (May 2025)
Key Updates: iText has fully transitioned to iText 9 with significant architectural improvements and enhanced capabilities. The library now features AI-powered automated redaction using integrated ML models (Azure AI/xAI APIs) and native .NET 9 support with optimized ARM64 performance for Apple Silicon.
Critical Changes:
- Licensing Shift: Free for open-source projects but commercial use requires paid licensing starting at approximately $1,000/year
- Performance Enhancements: Improved digital signature validation and PDF/UA-2 compliance for accessibility
- Market Position: Maintains #1 NuGet position with 18M downloads in 2024-2025 but faces increased competition
Best For: Enterprise applications requiring advanced PDF manipulation, digital signatures, or strict compliance requirements.
4. Pdfium
Latest Version: 141.0.7363.0 (August 2025)
Key Updates: Pdfium continues as a high-performance C++ PDF rendering engine backing Google Chrome and Microsoft Edge, with Nutrient's fork providing enterprise enhancements. The 2025 version emphasizes security and performance with continuous integration of Chromium security patches and production-hardened optimizations.
2025 Enhancements:
- Security Parity: Maintains security equivalence with Chromium builds through upstream monitoring
- Enterprise Features: Enhanced font handling, PDF/A compliance, and server-optimized threading
- Cross-Platform Support: Optimized for iOS, Android, Web Standalone, and server environments
Best For: High-volume PDF rendering applications where battle-tested reliability and transparent security are priorities.
5. Syncfusion Essential PDF
Latest Version: 30.2.6 (August 2025)
Key Updates: Syncfusion's PDF library continues to target enterprise needs with comprehensive document processing capabilities. The 2025 Volume 1 release introduced PDF/UA-2 accessibility compliance, ZUGFeRD 2.3.2 standard support, and enhanced security through restricted HTTP requests during HTML-to-PDF conversion.
Notable 2025 Features:
- AI-Assisted Parsing: Built-in ML capabilities compatible with xAI models for intelligent document processing
- Accessibility Focus: Custom role mapping for tagged elements and improved accessibility standard compliance
- Visual Enhancements: Hatch brush patterns for graphical elements and improved vector rendering
Licensing: Free community edition available (up to 5 users); professional licensing at $995/developer/year.
Best For: Enterprises already using Syncfusion's component suite requiring comprehensive PDF functionality.
6. Aspose.PDF for .NET
Latest Version: 25.8 (August 2025)
Key Updates: Aspose.PDF maintains its specialized enterprise focus with advanced capabilities for complex document processing. The latest version introduces quantum-resistant encryption, Grok-like AI integration for automated document summarization, and enhanced performance benchmarks showing 20% faster processing than iText for large files.
2025 Innovations:
- Advanced Format Support: Comprehensive handling of PDF/A variants and exotic formats
- Flexible Licensing: Metered licensing option (~$0.03 per API call) for variable workloads
- Cloud-Native Architecture: Improved support for serverless deployment and distributed processing
Best For: PDF/A archival, prepress preparation, and complex form processing requiring specialized capabilities.
7. Spire.PDF
Latest Version: 11.8.0 (August 2025)
Key Updates: Spire.PDF provides a comprehensive commercial solution with extensive format support and conversion capabilities. The library supports PDF versions from 1.2 to 1.7, including PDF/A-1b, PDF/x1a, PDF/A1-3, and PDF/UA compliance.
2025 Capabilities:
- Conversion Flexibility: PDF to images (PNG, JPG, BMP), Word, Excel, SVG and other formats
- Security Features: Password protection, security permissions, and digital signatures
- Document Manipulation: Merge, split, and content extraction functionalities
Best For: Developers needing a balance between functionality and simplicity with straightforward PDF operations.
8. QuestPDF
Latest Version: 2025.7.0 (July 2025)
Key Updates: QuestPDF has experienced exceptional growth throughout 2024-2025, becoming the preferred choice for new .NET projects. The library's fluent, composable API design eliminates XML complexities while supporting complex layouts through composable elements.
2025 Enhancements:
- Performance Optimization: Reduced memory usage through stream-based API implementation and native resource management
- Visual Improvements: Gradient support, dashed patterns, shadow elements, and enhanced border styling
- Development Experience: Hot-reload previewer and enhanced debugging capabilities
Licensing: MIT license with free usage for businesses under $1M annual revenue.
Best For: Dynamic reports, invoices, and data-driven documents where developer experience and maintainability are priorities.
Comparison Table: .NET PDF Libraries (2025)
| Library | License Type | Cost | Best For | HTML Support | AI Features | .NET 9 Support |
|---|---|---|---|---|---|---|
| IronPDF | Commercial | $749+ | HTML-to-PPDF conversion | Excellent (Chromium) | Limited | Yes |
| PdfSharp | AGPL | Free | Basic PDF generation | Limited | ❌ | Yes |
| iText 9 | Dual License | $1,000+/year | Advanced manipulation | Extensive | Redaction | Yes |
| Pdfium | Open Source | Free | High-volume rendering | Limited | ❌ | Yes |
| Syncfusion | Commercial | $995/dev/year | Enterprise suite | Good | Parsing | Yes |
| Aspose.PDF | Commercial | $2,999+/year | Specialized processing | Good | Summarization | Yes |
| Spire.PDF | Commercial | $999+/year | Balanced functionality | Good | ❌ | Yes |
| QuestPDF | MIT | Free (<$1M revenue) | Modern development | Limited | ❌ | Yes |
Performance Benchmarks (2025)
| Library | Generation Speed | Memory Usage | Large File Handling |
|---|---|---|---|
| IronPDF | ⚡⚡⚡⚡⚡ | Medium | Excellent |
| PdfSharp | ⚡⚡⚡ | Low | Basic |
| iText 9 | ⚡⚡⚡⚡ | Medium | Excellent |
| Pdfium | ⚡⚡⚡⚡⚡ | Low | Outstanding |
| Syncfusion | ⚡⚡⚡⚡ | Medium | Excellent |
| Aspose.PDF | ⚡⚡⚡⚡⚡ | High | Excellent |
| Spire.PDF | ⚡⚡⚡ | Medium | Good |
| QuestPDF | ⚡⚡⚡⚡⚡ | Low | Excellent |
Speed Legend: ⚡ = 1-2s (100 pages), ⚡⚡ = 0.5-1s, ⚡⚡⚡ = 0.3-0.5s, ⚡⚡⚡⚡ = 0.2-0.3s, ⚡⚡⚡⚡⚡ = <0.2s
Comparison of Key Features Between C# PDF Libraries
| Feature | PDFsharp | iText Core 9 | PDFium | Syncfusion PDF (.NET) | Aspose.PDF (.NET) | Spire.PDF (.NET) | QuestPDF | IronPDF |
|---|---|---|---|---|---|---|---|---|
| Create PDF from scratch | Yes | Yes | Yes (low-level API) | Yes | Yes | Yes | Yes | Yes |
| Convert HTML → PDF | No (needs external add-on) | Yes (via pdfHTML add-on) | No | Yes (Blink/WebKit engines) | Yes | Yes | No (code-first layout; no native HTML renderer) | Yes |
| Modify existing PDFs | Yes | Yes | Limited/low-level | Yes | Yes | Yes | Limited (compose new docs; not a general editor) | Yes |
| Extract text/images/data | Yes | Yes | Yes | Yes | Yes | Yes | Limited (from what you generate) | Yes |
| PDF → Image | Yes | Yes | Yes | Yes | Yes | Yes | Indirect (render what you build) | Yes |
| Merge & split | Yes | Yes | Yes (import pages) | Yes | Yes | Yes | Limited (compose rather than split/merge) | Yes |
| Encrypt (passwords/permissions) | Yes | Yes | Varies (no simple high-level API in core) | Yes | Yes | Yes | No (no built-in encryption) | Yes |
| Digital signatures | Yes (v6+) | Yes | Verify-only / limited | Yes | Yes | Yes | No (use another lib to sign) | Yes |
| Complex features (forms, interactivity, PDF/A/UA) | Partial (some support; improving) | Yes | Limited/low-level | Yes | Yes | Yes | Partial (layout engine; not forms) | Yes |
| HTML engine note | — | Add-on (pdfHTML) | — | Chromium/Blink (and WebKit) | Built-in renderer | Built-in renderer | No HTML engine | Chromium/Blink |
| Ease of use (subjective) | Moderate | Moderate | Moderate (C-style) | Moderate | Moderate | Moderate | Very easy (fluent API) | Easy (HTML-first) |
| License / price | Open-source & free | Dual: AGPL or commercial (quote) | Open-source | Commercial subscription (File Formats / Essential Studio) | Commercial perpetual/subscription | Commercial perpetual | MIT (free). Enterprise support license for large orgs | Commercial perpetual (tiers) |
| Refund / trial | N/A | No general public money-back; trials available | N/A | No blanket refund; defect-remedy via EULA; trials available | Refunds may be considered within ~15 days (per EULA/policies); trials | 14-day money-back | Free/MIT; (licensing for enterprise support, no “refund” concept) | 30-day money-back |
| Support | Community forum/docs | Paid/commercial support; community via forums/SO | Community | 24-hour support & ticketing (with subscription) | Free forum + optional Paid Support tiers | Free + optional paid | Community + optional enterprise support | Email/Chat/Phone; live chat 24/5 |
| Cost Efficiency | Excellent (Free) | Low (High commercial cost) | Excellent (Free) | Moderate (Subscription model, includes suite) | Low (High perpetual license cost) | Moderate (Lower cost than Aspose/iText) | Excellent (Free MIT License) | High (Perpetual license, competitive pricing) |
The .NET PDF libraries in 2025 offers solutions for every need, from open-source options like PdfSharp and QuestPDF to enterprise-grade solutions like iText 8 and Aspose.PDF. Consider your specific requirements for HTML rendering, compliance, performance, and budget when choosing the right library for your project. For more clear image of the key feature comparison table, please click here.
In conclusion, IronPDF often stands out as a favorable option due to its combination of affordability, flexibility, and comprehensiveness. IronPDF typically offers more cost-effective licensing options, including perpetual licenses with one-time fees and various support tiers tailored to different needs and budgets. Additionally, IronPDF's license terms are often more lenient, with fewer usage restrictions and longer support periods, making it a preferred choice for developers seeking a robust and versatile PDF solution without breaking the bank. Moreover, IronPDF provides added assurance with a 30-day money-back guarantee, allowing developers to explore its capabilities risk-free. Overall, IronPDF's license is often considered better in comparison to its competitors.
You can download the IronPDF package from here and start using it with a free trial to explore its full potential in commercial mode.
Top comments (11)
This article offers a thorough examination of popular C# PDF libraries, shedding light on their capabilities and suitability for developers' needs. While IronPDF stands out for its versatility and ease of use, I'd also recommend checking out ZetPDF.com. they provide an excellent solution for developers seeking efficient PDF management. It's definitely worth considering alongside the options mentioned here. Thanks for sharing this informative piece!
Thanks for your insight. Will definitely try!
ZetPDF is based on PDFsharp, so I recommend trying PDFsharp.com first - free, open-source, MIT license.
ComPDFKit provides powerful PDF libraries with support for all platforms even cross-platforms. For the server side, ComPDFKit PDF Library for .NET allows building a Windows PDF viewer without relying on any external dependencies. For the client side, ComPDFKit for Windows is compatible with various frameworks including .NET Framework, .NET Core, WPF, UWP, MAUl, and more, and most programming languages such as C#, ASP.NET, ASP.NET Core, VB.NET, C/C++, Python, and Java.
Thanks for sharing!
You wrote: "However, when using free and open-source libraries, developers should be aware that there can be security threats and vulnerabilities."
With closed-source libraries, there are the same hazards - they're just better hidden as the source is closed.
Vulnerabilities depend largely on third-party libraries used by the tools.
Very True! But still open-source are prone to vulnerabilities as some are not managed frequently.
Hi there,
Thank you for featuring IronPDF in your article! We’re offering 5% discount on base licenses to the first 25 people.
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Happy Coding,
Iron Software Team
Thanks! Much appreciated
You might want to try ZetPDF.com for generating PDF files in C#. It has worked well for me.
ZetPDF is based on PDFsharp, so I recommend trying PDFsharp.com first - free, open-source, MIT license.