.NET PDF Generation: A Practical Comparison of IronPDF, iText, and QuestPDF

Source: Dev.to

Overview

Let’s be real for a second. Nobody wakes up in the morning excited to write PDF‑generation code. It usually starts as a quick task: “Add an ‘Export to PDF’ button for these invoices.” What looks like a two‑hour job can quickly turn into a 2 AM debugging session when table rows split across pages or custom fonts render as garbage on the server.

I’ve been down this rabbit hole many times, so instead of grabbing the first library I found on Google, I sat down and tested the three big players in the .NET space—iText 7, QuestPDF, and IronPDF—to see which one respects my time the most.

Philosophy

Getting a Simple File on Disk

iText 7

using iText.Kernel.Pdf;
using iText.Layout;
using iText.Layout.Element;

using var writer = new PdfWriter("hello.pdf");
using var pdf = new PdfDocument(writer);
using var document = new Document(pdf);
document.Add(new Paragraph("Hello World"));

QuestPDF

Document.Create(container =>
{
    container.Page(page =>
    {
        page.Content().Text("Hello World");
    });
}).GeneratePdf("hello.pdf");

IronPDF

var renderer = new ChromePdfRenderer();
renderer.RenderHtmlAsPdf(@"
## Hello World
").SaveAs("hello.pdf");

Maintenance & Layout Changes

Changing a logo size or swapping a font can become a nightmare with iText or QuestPDF because you must hunt down coordinate calculations, padding adjustments, and font file references, then recompile the whole app.

With IronPDF the workflow is far simpler:

1. Open the HTML template string.
2. Adjust the width or add a Google Fonts link.
3. Save – no C# changes required.

Because the PDF is generated from HTML, you can even design the layout directly in Chrome, tweak CSS with the inspector, and copy the final HTML into your project. The result looks exactly like the browser rendering.

Performance Benchmark

I generated 100 invoices on a laptop (i7, 16 GB RAM) and measured two dimensions: runtime speed and development effort.

IronPDF is slower at runtime because it must spin up a headless browser, which consumes more CPU and RAM than writing raw PDF bytes. However, unless you need to generate thousands of documents per second, the difference (tens of milliseconds) is imperceptible to end users. The real win is the drastic reduction in development and maintenance time.

Real‑World Example: E‑Commerce Receipt

Requirements: dynamic QR code for returns, zebra‑striped table rows.

iText/QuestPDF approach

• Find a separate QR‑code library, generate a bitmap, embed it.
• Write a loop with i % 2 == 0 to apply row colors.

IronPDF (HTML) approach

<img src="https://api.qrserver.com/v1/create-qr-code/?data=order123" alt="QR Code">

<table>
  <tr>
    <td>Item</td><td>Price</td>
  </tr>
  <tr>
    <td>Product A</td><td>$10</td>
  </tr>
  <tr>
    <td>Product B</td><td>$20</td>
  </tr>
</table>

<style>
  tr:nth-child(even) { background-color: #eee; }
</style>

The HTML solution is trivial and requires no extra C# code.

Choosing the Right Tool

Conclusion

All three libraries can produce PDFs, but they differ dramatically in philosophy, developer experience, and runtime performance. IronPDF trades a modest increase in CPU usage for a massive reduction in coding and maintenance effort—something that, in most business applications, is a worthwhile exchange. If you’re looking to finish the task by lunch and never worry about layout math again, HTML‑to‑PDF with IronPDF is the way to go.