The 3 C# PDF Libraries Every Developer Must Know

The PDF stands for Portable Document Format. The PDF provides flexibility, which means that it can be modified in any way the author desires. Today, we have access to many other great digital formats such as DOCX and PPTX.

However, PDF is still widely popular due to its long history of success and wide compatibility with devices. Some people would argue that PDF is more convenient than these newer formats because it can be viewed on different devices without any conversion required.

Sometimes the simplest of tasks can get complicated when it comes to PDFs, especially when we need to modify a PDF programmatically. In this article, we will cover common problems faced by developers and how to solve them.

These are the common problems faced by developers while editing PDF documents programmatically in their applications.

• How do you customize or edit fonts on your printed documents with little or no effort?
• The proper way to print multiple pages on a single sheet.
• What features can be added or taken away from a PDF file?
• How do I create a PDF file that is not editable?

One of the main problems with PDFs is that it's difficult to modify them. You need to know how it works to modify it and this makes the process complicated and time-consuming.

Modifying PDF programmatically is not easy, but with the right tool, you can make the modification easier by reading the original file's metadata and extracting specific information from the source code of your system.

So, in this article, I will talk about three PDF Generating libraries that developers must know for PDF modification purposes.

1. IronPDF: C# PDF Library

IronPDF is a C# PDF library that allows for fast and efficient reading and writing of PDF files. It does not use external tools or SDKs for editing or interacting with the data. It can run with minimal memory usage and only requires .NET Framework 4.5 or higher and .NET Core 2.0 to function. It supports the latest version of the .NET Framework 7.

When it comes to creating PDFs in the .NET core, there are plenty of libraries. However, when you have a complex project and need the best possible performance out of your PDF generation, IronPDF is an ideal choice.

It's one of the most advanced and powerful PDF libraries available today. From encoding to security, IronPDF provides the same high-quality experience for developers as it does for end users. It is a standalone pdf component to use.

IronPDF library can be used to create, edit and manipulate PDF files with just a few lines. It supports various kinds of operations for editing and manipulating PDF files including text extraction and text insertion in existing pdf files.

The library has features that make it easier for developers to create secure, convenient, and customizable HTML to PDF conversions and modify pdf files. These features include pdf locks, editing restrictions, and pdf security.

Developers also have access to an API for customizing the generated output without having to use any additional software or hardware. Some of its features include the ability to create responsive layouts; the creation of headers and footers; margins; and the conversion of images into PDFs. IronPDF also has tools for converting PDFs into XML, XPS, or JPG formats.

You can also convert an HTML string or HTML file to a PDF document. IronPDF uses HTML strings to generate pdf documents. It makes PDF creation very easy. The main goal of IronPDF is to be a simple, yet powerful and flexible library for developers to use in creating PDF documents from images or other sources. Let's have a look at the code example of IronPDF.

Code Example:

HTML to pdf:

using IronPdf;
 
var Renderer = new IronPdf.ChromePdfRenderer();
using var PDF = Renderer.RenderHtmlAsPdf("<h1>Html with CSS and Images</h1>")
PDF.SaveAs("pixel-perfect.pdf");

Images to PDF:

// PM> Install-Package IronPdf
using IronPdf;
using System.IO;
using System.Linq;
 
// One or more images as IEnumerable.  This example selects all JPEG images in a specific folder.
var ImageFiles = System.IO.Directory.EnumerateFiles(@"C:\project\assets").Where(f => f.EndsWith(".jpg") || f.EndsWith(".jpeg"));
 
// Convert the images to a PDF and save it.
ImageToPdfConverter.ImageToPdf(ImageFiles).SaveAs(@"C:\project\composite.pdf");

Headers & Footers:

// PM> Install-Package IronPdf
using IronPdf;
 
 
IronPdf.ChromePdfRenderer Renderer = new IronPdf.ChromePdfRenderer();
 
 
  // Build a footer using html to style the text
  // mergable fields are:
  // {page} {total-pages} {url} {date} {time} {html-title} & {pdf-title}
  Renderer.RenderingOptions.HtmlFooter = new HtmlHeaderFooter()
  {
 
      MaxHeight = 15, //millimeters
      HtmlFragment = "<center><i>{page} of {total-pages}<i></center>",
      DrawDividerLine = true
  };

You have seen that the usage of this library is very easy and simple. It allows installation easily using NUGET packages. We can modify the existing pdf documents. For more tutorials, you can visit this link.

License

The free version is available for development purposes. IronPDF has variations in its pricing plan for individuals and companies. Let's have a look at the pricing plan.

2. PDFTron

PDFTron C# is a pdf library that provides a variety of utility functions for creating, editing, and manipulating pdf documents. PDFTron C offers many features that are important to an organization’s digital transformation.

The library’s high performance, easy installation, and portability make it an invaluable tool for companies wanting to create PDF documents. The feature-rich environment also ensures that companies can utilize PDF as a document format to their fullest potential. PDFTron C# pdf library is a powerful and intuitive library, which allows developers to create, modify and extract text from PDF files.

This library is designed to be modular and as such can be used in any kind of project, not just software development. You can convert pdf documents to other formats. You can arrange PDF pages too.

The new library addresses significant scalability issues existing in traditionally primitive methods of creating, storing, and manipulating digital soft documents. It will store the metadata along with resultant files in the native format while embedding the content into XML or JSON formats if necessary.

This feature allows users to explore dynamic content from within modern computing environments without having to download cumbersome packages such as ZIP or RAR files before conversion. Let's have a look at the code examples:

Code Example

Insert Pages:

PDFDoc new_doc = new PDFDoc();
int page_num = 15;
for (int i = 1; i <= page_num; ++i)
{
    PDFDoc in_doc = new PDFDoc(filename + "_split_page_" + i + ".pdf");
    new_doc.InsertPages(i, in_doc, 1, in_doc.GetPageCount(), PDFDoc.InsertFlag.e_none);
}
new_doc.Save(output_filename + "_merge_pages.pdf", SDFDoc.SaveOptions.e_linearized);

Blank PDF:

// use the empty constructor to create a blank PDF
PDFDoc doc = new PDFDoc();

// optionally perform some document processing using read write operations 
// found under 'Editing Page Content' or 'Page Manipulation'

// save the document to the filesystem
doc.Save(output_filename, SDFDoc.SaveOptions.e_linearized);

// optionally save the document to a memory buffer
byte[] buf = doc.Save(SDFDoc.SaveOptions.e_linearized);

In the above examples, we can see that it is easy to use in our programs. Somehow, the parameters are looking difficult to understand for the beginner. PDFTron uses some advanced concepts. So, for the beginner, it will be a difficult task to understand its functions. But overall, PDFTron has good performance and output.

License

If we talk about its license, then we don't have any information because we have to contact support to discuss its pricing plan.

3. QuestPDF

QuestPDF is a cutting-edge library that will allow you to make PDFs in your .NET application by offering a high-level, user-friendly API in C#. It has documentation that shows how to manipulate PDFs. There are also a bunch of examples and design patterns there to get you up and running quickly!

This library is created for professionals to use when designing document layouts and considering pagination. Alternative approaches, such as HTML-based converters, are not designed for this and so often produce unpredictable results. QuestPDF was built using SkiaSharp, an open-source graphics library.

The PDFs created by QuestPDF are high quality, meaning you'll get an exceptional result with less effort. It has a well-optimized layout engine that can generate more than 1000 PDF files per minute per core. It is also thread-safe.

Let's take a look at QuestPDF and how we can use QuestPDF in our program.

Code Example

using QuestPDF.Fluent;
using QuestPDF.Helpers;
using QuestPDF.Infrastructure;

// code in your main method
Document.Create(container =>
{
    container.Page(page =>
    {
        page.Size(PageSizes.A4);
        page.Margin(2, Unit.Centimetre);
        page.Background(Colors.White);
        page.DefaultTextStyle(x => x.FontSize(20));
        
        page.Header()
            .Text("Hello PDF!")
            .SemiBold().FontSize(36).FontColor(Colors.Blue.Medium);
        
        page.Content()
            .PaddingVertical(1, Unit.Centimetre)
            .Column(x =>
            {
                x.Spacing(20);
                
                x.Item().Text(Placeholders.LoremIpsum());
                x.Item().Image(Placeholders.Image(200, 100));
            });
        
        page.Footer()
            .AlignCenter()
            .Text(x =>
            {
                x.Span("Page ");
                x.CurrentPageNumber();
            });
    });
})
.GeneratePdf("hello.pdf");

Its syntax is very difficult to understand for the beginner. In the above example, we can see how complex its structure is in comparison to IronPDF and PDFTron. You have to write a lot of code lines to perform simple operations. But it is free for production. So, it is a plus point.

License

If we are talking about a license then its license comes under the MIT license. It is open source right now. So, developers can use it for free. But its features are limited. It has not a large variety of operations. It offers some basic operations.

Conclusion

In last words, I will compare the pricing plans of these libraries.

IronPDF has 3 pricing plans from individual to company. It is free for development and has a 30-day free trial too. The prices are very reasonable. It starts from $499 only.

PDFTron has a pricing plan too but it is not visible. You have to contact support to get any information about the price. So, there is a chance that they vary prices from person to person.

QuestPDF is totally free but its functions are limited. It has no very complex functionalities. It offers only basic functionalities.

Choosing the PDF library depends on you. You can buy it according to your needs. But IronPDF is the cheapest and fully functional library that I have used.