PDFSharp vs IronPDF: Technical Comparison Guide

When .NET developers need to create PDF documents programmatically, they often consider PDFSharp and IronPDF. PDFSharp has been a popular choice for creating PDFs through a coordinate-based drawing approach, while IronPDF offers HTML-to-PDF conversion with modern CSS support. This comparison examines both libraries, analyzing their architectural differences, API patterns, and suitability for different development scenarios.

PDFSharp is a low-level PDF creation library that allows developers to generate PDF documents through a programmatic, coordinate-based approach. Released under the MIT license, PDFSharp grants the developer community freedom in usage and modification without licensing costs.

PDFSharp primarily functions as a tool for drawing and compiling PDFs from scratch. The library uses a GDI+ style API where developers position every element using X,Y coordinates. This approach requires calculating exact positions for text, images, lines, and rectangles—similar to drawing on a canvas.

Key characteristics of PDFSharp include:

• Coordinate-Based Drawing: Every element requires explicit X,Y positioning
• MIT License: Free to use, modify, and distribute
• GDI+ Style API: Uses XGraphics, XFont, XBrush, and XPen classes
• Manual Page Management: Developers handle page creation and overflow manually
• No HTML Support: Cannot directly convert HTML/CSS to PDF
• Lightweight: No external dependencies, simplifies deployment

PDFSharp is sometimes mistakenly assumed to be an HTML-to-PDF converter, which it is not. Its purpose is dedicated to programmatic PDF document creation only. While there is an add-on, HtmlRenderer.PdfSharp, intended to provide HTML rendering capabilities, it only supports CSS 2.1, with no support for modern CSS features like flexbox and grid, and has limitations such as broken table rendering.

IronPDF is a comprehensive .NET library that provides native HTML-to-PDF conversion using an embedded Chromium rendering engine. The ChromePdfRenderer class converts HTML content with full support for HTML5, CSS3, and JavaScript—including modern layout features like flexbox and grid.

Unlike PDFSharp's coordinate-based approach, IronPDF allows developers to use web technologies for document creation. Instead of calculating X,Y positions, developers write HTML and CSS to define document structure and styling. The Chromium engine handles text flow, page breaks, and element positioning automatically.

The fundamental difference between PDFSharp and IronPDF lies in their approach to document creation: manual coordinate-based drawing versus HTML-based rendering.

For developers with web development experience, IronPDF's HTML-based approach transfers existing skills to PDF generation. For developers requiring fine-grained control over individual pixels or coming from GDI+ backgrounds, PDFSharp provides familiar patterns.

Converting HTML content to PDF demonstrates the fundamental capability gap between these libraries.

PDFSharp cannot convert HTML to PDF. The library requires manual rendering where developers must parse HTML themselves and draw each element using coordinates. IronPDF's ChromePdfRenderer natively accepts HTML strings and renders them with full CSS support through the embedded Chromium engine.

This capability difference significantly impacts development time. Creating a styled document in PDFSharp requires calculating positions for every element, while IronPDF developers write standard HTML/CSS.

Modifying existing PDFs to add text shows different approaches to document manipulation.

PDFSharp uses PdfReader.Open() to load an existing PDF, then obtains an XGraphics object to draw text at specific X,Y coordinates using DrawString(). The developer must calculate exact positioning.

IronPDF uses PdfDocument.FromFile() to load the PDF, then creates a TextStamper object with alignment properties like VerticalAlignment.Middle and HorizontalAlignment.Center. The ApplyStamp() method handles positioning based on these alignment settings.

Adding images to PDFs demonstrates the different paradigms between coordinate-based and HTML-based approaches.

PDFSharp requires loading the image with XImage.FromFile(), then drawing it at specific coordinates using gfx.DrawImage(image, x, y, width, height). Text must be positioned relative to the image using calculated coordinates.

IronPDF allows embedding images using standard HTML <img> tags with CSS styling. The Chromium engine handles image loading, sizing, and positioning through CSS properties. Alternatively, ImageStamper can add images to existing PDFs with alignment-based positioning.

For teams evaluating PDFSharp migration to IronPDF, understanding the API mappings helps estimate development effort.

The most significant change is eliminating PdfSharp.Drawing—IronPDF replaces coordinate-based drawing with HTML/CSS layouts.

PDFSharp's GDI+ approach creates significant development overhead:

• Calculate exact X,Y positions for every element: Each text block, image, and shape requires manual positioning
• Manually track content height for page overflow: Developers must detect when content exceeds page bounds
• Handle line wrapping and text measurement yourself: Long text requires calculating where to break lines
• Draw tables cell by cell with border calculations: Each table cell requires individual positioning and border drawing
• Manage multi-page documents with manual page breaks: Detecting and handling page boundaries is manual

IronPDF eliminates these concerns by leveraging the Chromium layout engine. Text flows naturally, tables resize automatically, and page breaks occur at appropriate points—all controlled through standard CSS.

Applications requiring modern CSS layouts, automatic pagination, or HTML template-based generation benefit significantly from IronPDF's approach.

Several factors drive teams to evaluate IronPDF as an alternative to PDFSharp:

Development Time Reduction: PDFSharp requires calculating X,Y positions for every element. Teams spending significant time on coordinate calculations and page break handling often find HTML/CSS-based generation dramatically faster.

Modern CSS Requirements: PDFSharp cannot render modern CSS features like flexbox, grid, or CSS3 selectors. Applications requiring contemporary web layouts must use IronPDF's Chromium engine.

Maintainability Concerns: Coordinate-based PDFSharp code is difficult to modify—changing one element often requires adjusting positions of subsequent elements. HTML/CSS templates are significantly easier to update.

Web Development Skills Transfer: Teams with HTML/CSS expertise can apply existing skills to PDF generation with IronPDF, rather than learning GDI+-style drawing APIs.

Complex Document Requirements: Documents with tables, mixed content, or dynamic layouts become increasingly difficult with coordinate-based positioning. HTML templates handle complexity more naturally.

Active Maintenance Needs: PDFSharp receives infrequent updates. Teams requiring regular security patches and feature updates benefit from IronPDF's active development.

The choice between PDFSharp and IronPDF depends on your project requirements:

Consider PDFSharp if: Your project requires fine control over document rendering without additional dependencies, budget constraints prohibit commercial licensing, you're comfortable with coordinate-based positioning, and your documents don't require HTML/CSS rendering.

Consider IronPDF if: You need modern HTML-to-PDF conversion with CSS3 support, your team has web development skills to leverage, you want automatic text flow, tables, and page break handling, development time reduction is important, or you need active maintenance and support.

To evaluate IronPDF for your PDF generation needs:

1. Install via NuGet: Install-Package IronPdf
2. Review the getting started documentation
3. Explore HTML to PDF tutorials for conversion patterns
4. Check the API reference for complete method documentation

PDFSharp and IronPDF serve different needs in the .NET PDF generation space. PDFSharp is suitable for projects requiring fine control over document rendering without additional dependencies, where budget constraints are a factor and coordinate-based drawing is acceptable. However, it falls short for projects necessitating modern web standards or dynamic content delivered via HTML.

IronPDF surpasses PDFSharp in situations necessitating modern HTML-to-PDF conversion, thanks to its robust features supporting CSS3, HTML5, and high-level document manipulation. While it comes with a commercial license, the increased productivity and modern capabilities often justify the investment.

Understanding your project's requirements—whether it's cost constraints, the need for modern web support, or intricate document design—will guide the choice between these two library offerings. The coordinate-based nature of PDFSharp creates development overhead that IronPDF's HTML-based approach eliminates, but PDFSharp's MIT license and lightweight footprint remain attractive for appropriate use cases.

Evaluate your complete requirements—HTML/CSS support needs, development timeline, maintenance considerations, and budget—when selecting between these libraries. The architectural differences are fundamental and impact every aspect of PDF generation workflow.