Render a PDF to an image in .NET — with a pure-C# PDF engine

Most PDF libraries in .NET are wrappers. PDFium, MuPDF, Ghostscript — solid engines, but they ship native binaries you P/Invoke into. That buys you per-RID packages, Native AOT friction, the "works on my box, throws DllNotFoundException in the Alpine container" dance, and a deployment story that's never quite boring.

as the 2D canvas to turn the parsed page into pixels. SkiaSharp carries a native component.

So the rule of thumb:

• Parsing, text extraction, editing, optimizing → fully managed, ship no native code.
  


• Rasterizing a page to an image → add SkiaSharp.

SkiaSharp is a well-behaved, broadly-supported cross-platform dependency, so this is a very different proposition from bundling and P/Invoking a PDF engine yourself — but it's not nothing, and you should know exactly where the line is.

It's not just a renderer

Rendering is the flashy demo, but the managed core is the actual point. A few things that need only the core package (no SkiaSharp):

Extract text:

using var doc = PdfDocument.Load("input.pdf");

string text = doc.GetPage(0).ExtractText(doc);

Edit an existing document:

using PdfLibrary.Editing;



using var doc = PdfDocument.Load("input.pdf");

var edit = doc.Edit();

edit.Pages.RemoveAt(2);     // delete the 3rd page

edit.Pages.Rotate(0, 90);   // rotate the 1st page 90°

edit.Save("edited.pdf");

Optimize / shrink:

using PdfLibrary.Optimization;



using var doc = PdfDocument.Load("input.pdf");

using var output = File.Create("optimized.pdf");

PdfOptimizer.Optimize(doc, output);   // lossless by default

Threading

PdfLibrary is built for the one-document-per-request model — the standard pattern for ASP.NET Core. Load a PdfDocument per request, render it on its own target, dispose both. Under that model it's thread-safe, and the process-wide caches (glyph paths, font resolution, ICC profiles) are synchronized. The one thing you must not do is share a single PdfDocument (or a SkiaSharpRenderTarget) across threads.

Links

• NuGet:
  


• Source (MIT): github.com/lxman/PdfLibrary
  


• Targets .NET 8, 9, and 10.

If you try it and something doesn't render the way you expect, open an issue with the PDF attached — edge cases in the wild are how this kind of library gets better.