SelectPdf.Universal 26.5.0

SelectPdf Library for .NET — Cross-Platform (Windows, Linux, macOS)

SelectPdf is a professional PDF library for creating, writing, editing and reading PDF files entirely in C#/VB.NET — no Adobe Acrobat required. It includes a state-of-the-art HTML to PDF converter built on Chromium (HTML5, CSS3, web fonts, modern JavaScript) and a Word to PDF converter (DOCX, DOC, RTF and more).

This package is cross-platform: it runs on Windows (x64, x86), Linux (x64, ARM64) and macOS (Apple Silicon), on .NET 10, .NET 9, .NET 8 and .NET Standard 2.0 (consumable from .NET Framework 4.6.1+). It runs in Docker containers and on Microsoft Azure, Amazon Web Services and Google Cloud. Verified with the .NET 11 release candidate (RC 1) on Windows x64, Linux x64 and ARM64, and macOS.

Installation

dotnet add package SelectPdf.Universal
# engine: win-x64, win-x86, linux-x64, linux-arm64 or osx-arm64
dotnet add package SelectPdf.Universal.Native.win-x64

The managed SelectPdf.Universal package is AnyCPU and works on every platform (the assembly is SelectPdf.Universal.dll, namespace SelectPdf.Universal). Add the SelectPdf.Universal.Native.<rid> package that matches your runtime: it deploys the Chromium engine (HTML to PDF / HTML to image) and the native PDF tool (PDF to text / PDF to image) next to your application.

For an application that runs on one platform, one package installs both: SelectPdf.Universal.Windows (Windows x64), SelectPdf.Universal.Linux, SelectPdf.Universal.Linux.Arm64 or SelectPdf.Universal.MacOS. Reference one of them or the two packages above, not both.

Quick start

HTML to PDF

using SelectPdf.Universal;

HtmlToPdf converter = new HtmlToPdf();
converter.Options.PdfPageSize = PdfPageSize.A4;
converter.Options.MarginTop = 20;
converter.Options.MarginBottom = 20;

using PdfDocument doc = converter.ConvertUrl("https://selectpdf.com");
// or: converter.ConvertHtmlString("<h1>Hello</h1>", baseUrl);
doc.Save("page.pdf");

Asynchronous conversion

HtmlToPdf converter = new HtmlToPdf();
using PdfDocument doc = await converter.ConvertUrlAsync(
    "https://selectpdf.com", cancellationToken);
doc.Save("page.pdf");

HTML to PDF in an ASP.NET Core endpoint

using SelectPdf.Universal;

var app = WebApplication.CreateBuilder(args).Build();

// POST an HTML string, get a PDF back
app.MapPost("/pdf", async (HttpRequest request) =>
{
    string html = await new StreamReader(request.Body).ReadToEndAsync();

    HtmlToPdf converter = new HtmlToPdf();
    converter.Options.PdfPageSize = PdfPageSize.A4;
    using PdfDocument doc = await converter.ConvertHtmlStringAsync(html);
    byte[] pdf = doc.Save();

    return Results.File(pdf, "application/pdf", "document.pdf");
});

app.Run();

Word to PDF

WordToPdf converter = new WordToPdf();
// optional: archival output
converter.Options.PdfStandard = PdfStandard.PdfA2B;

using PdfDocument doc = converter.ConvertFile("contract.docx");
doc.Save("contract.pdf");

Create a PDF from scratch

using PdfDocument doc = new PdfDocument();
PdfPage page = doc.AddPage();

PdfFont font = doc.Fonts.Add(PdfStandardFont.Helvetica);
font.Size = 20;
page.Add(new PdfTextElement(50, 50, "Hello world!", font));

// html, images, shapes, links and bookmarks can be added too
page.Add(new PdfHtmlElement(50, 100, 400,
    "<p>Some <b>html</b> content</p>", null));

doc.Save("hello.pdf");

Redact content

using PdfRedactionManager redaction = new PdfRedactionManager();
redaction.Load("statement.pdf");
redaction.OverlayText = "[REDACTED]";
// text
redaction.AddRedaction("John Smith", false, true);
// pattern
redaction.AddRedaction(
    new System.Text.RegularExpressions.Regex(@"\d{3}-\d{2}-\d{4}"));
// the content is removed from the file, not just covered
redaction.Save("statement-redacted.pdf");

Sign and validate signatures

using PdfSecurityManager signer = new PdfSecurityManager();
signer.Load("contract.pdf");
signer.Sign("certificate.pfx", "pfxPassword");
signer.Save("contract-signed.pdf");

using PdfSecurityManager validator = new PdfSecurityManager();
validator.Load("contract-signed.pdf");
foreach (var result in validator.ValidateSignatures())
    Console.WriteLine($"{result.SignerName}: {result.Status}");

Encrypt, merge, accessibility and archiving

using PdfDocument doc = new PdfDocument("report.pdf");
doc.Append("appendix.pdf");                       // merge
doc.Security.OwnerPassword = "owner";             // AES-256 by default
doc.Security.UserPassword = "user";
doc.Security.CanCopyContent = false;
doc.Save("report-protected.pdf");

HtmlToPdf converter = new HtmlToPdf();
converter.Options.PdfStandard = PdfStandard.PdfA4;                 // PDF/A-4
// tagged, PDF/UA-2
converter.Options.AccessibilityStandard = PdfUAStandard.UA2;
converter.Options.Title = "Annual report";
converter.Options.Language = "en-US";

PDF to text and PDF to image

using PdfToText pdfToText = new PdfToText();
pdfToText.Load("document.pdf");
string text = pdfToText.GetText();

using PdfRasterizer rasterizer = new PdfRasterizer();
rasterizer.Load("document.pdf");
byte[][] pngPages = rasterizer.ConvertToImages();

Main Features

PDF documents

• Generate PDF documents from scratch; load, modify and save existing PDFs
• Page elements: text, images (PNG, JPEG, GIF, BMP, WebP, TIFF), HTML, HTML rendered as images, Word content, shapes, links, attachments, notes
• Reusable templates, headers and footers (also per page), watermarks and stamps, page numbering, bookmarks, page rotation
• Merge PDF documents; resize and reflow existing pages; PDF portfolios; open actions
• AcroForm filling and flattening
• Redaction: remove text (by value or regular expression), images, graphics, links and form fields from marked areas, optionally with an overlay label
• Compression of images, content streams and fonts
• PDF to text (extract, search, text in a region) and PDF to image (PNG, JPEG, BMP, GIF, TIFF)

HTML to PDF converter (Chromium)

• Convert any web page or HTML string to PDF, synchronously or asynchronously with cancellation
• Page size, orientation, margins, content resizing, page breaks, repeated table headers, @media screen and print
• HTML headers and footers, automatic bookmarks, internal and external links, table of contents, web element locations
• HTTP headers, cookies, POST data, authentication, login forms, proxy servers
• Conversion delay, navigation timeout, lazy image loading, JavaScript control, startup and post-loading scripts, custom CSS, element clicks
• Partial conversion (CSS selector), hidden elements, single-page PDF output
• HTML to image (PNG) converter
• Up to 8 conversions run concurrently (configurable)

Word to PDF converter

• DOCX, DOCM, DOTX, DOTM, DOC, DOT, RTF, TXT, WordML, HTML and Markdown input, encrypted documents included
• Keep the document's own page sizes or reflow onto the page size and margins you choose
• Outline from headings or Word bookmarks; headers, footers, security, PDF/A and PDF/UA output like the HTML converter
• Word content in PDF pages, headers and footers

Security and signatures

• RC4, AES and AES-GCM encryption, up to 256-bit keys (AES-256 by default), granular permissions, optional unencrypted XMP metadata
• Digital signatures (SHA-256) with visible appearance and RFC-3161 time stamps
• Signature validation: integrity, trust chain, coverage, time stamp and revocation status

Standards and accessibility

• PDF/A-1b, PDF/A-2b, PDF/A-3b, PDF/A-3u, PDF/A-3a, PDF/A-4, PDF/A-4e, PDF/A-4f and PDF/X-1a
• Tagged, accessible PDF: PDF/UA-1 and PDF/UA-2, from HTML, from Word and from scratch
• PDF/A-3 associated files; ZUGFeRD / Factur-X electronic invoices; custom XMP metadata schemas

Docker

The Linux engine packages bundle the Chromium libraries, so a Docker image needs no apt-get lines. Reference SelectPdf.Universal.Native.linux-x64 (or linux-arm64 for an ARM64 image) and build with the official .NET images:

FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
WORKDIR /src
COPY . .
RUN dotnet publish -c Release -o /app

FROM mcr.microsoft.com/dotnet/aspnet:10.0
WORKDIR /app
COPY --from=build /app .
ENTRYPOINT ["dotnet", "YourApp.dll"]

Reference one engine package per build: the packages install into the same folder, so a project that develops on Windows and deploys to Linux picks the package by runtime, for example with a Condition on $(RuntimeIdentifier).

Deployment notes

• Linux: the native packages bundle the Chromium shared libraries, so conversions run on minimal distributions and in containers without apt-get. Requires glibc 2.30+ (Debian 11+, Ubuntu 20.04+, RHEL 9+). Alpine (musl) is supported through the remote engine: reference SelectPdf.Universal alone and set RenderingEngine.ChromiumRemote.
• Docker: the official .NET images work as they are on Linux, with no --shm-size or GPU; Windows containers need Windows Server Core with the core Windows fonts installed.
• Azure: App Service (Basic plan or above) and Azure Functions on a Dedicated or Premium plan, on Windows and Linux.
• Cloud: step-by-step guides for Azure App Service, Azure Functions (Dedicated and Premium plans), Azure Container Apps, AWS Lambda (container image, x64 and arm64), AWS Elastic Beanstalk and Google Cloud Run.
• Fonts: Linux hosts and container images often have no fonts, and the fonts built into the library cover Latin scripts only. Add SelectPdf.Universal.Fonts (Noto fonts for every script, copied next to the application on Linux and macOS) to render every language; your own fonts go in a fonts folder next to the application, on every platform.
• Engine hosting: the Chromium engine runs inside your application when the native package matches your process architecture (a 32-bit Windows process, such as a default Windows App Service worker, uses win-x86); with another package, conversions run in a separate engine process automatically. Set GlobalProperties.ChromiumEngineHostMode = ChromiumEngineHostMode.OutOfProcess to run every conversion in its own engine process.
• Native debug symbols: SkiaSharp 3.119.2 and later ship libSkiaSharp.pdb / libHarfBuzzSharp.pdb (about 300 MB for the Windows architectures) as runtime files, which the application never uses (SkiaSharp #3519). This package leaves them out of your build and publish output and your .deps.json; set <SelectPdfKeepNativeSymbols>true</SelectPdfKeepNativeSymbols> in your project to keep them.

Migrating to SelectPdf.Universal

SelectPdf.Universal is the cross-platform successor of the Windows-only Select.Pdf / Select.Pdf.NetCore packages. It keeps their classes and members, so porting is mostly mechanical:

1. Replace the Select.Pdf* package references (and the Chromium / Blink companion packages) with SelectPdf.Universal plus a SelectPdf.Universal.Native.<rid> package, and remove Select.Html.dep, Select.Tools.dep and the old engine folders from the project.
2. Change using SelectPdf; to using SelectPdf.Universal;.
3. Replace System.Drawing types: PdfColor for colors, SelectPdf.Universal.Drawing for points, rectangles and sizes, PdfFont / PdfSystemFont for fonts, Stream or byte[] for images (HtmlToImage and PdfRasterizer return encoded images as byte[]).
4. HTML is rendered with Chromium only: remove WebKit / Blink engine selection and settings, rename CefEnginePath to ChromiumEnginePath, and review the output of pages that rendered with the WebKit default.
5. Use PdfDocument.Append instead of PdfMergeManager. PdfPrinter and the Select.Pdf.Extras add-on have no counterpart.

License keys issued for version 26 or later keep working. The documentation's Migrating to SelectPdf.Universal topic lists every change, the defaults that differ and how fonts are found on each platform.

Documentation & Support

• Documentation: https://selectpdf.com/pdf-library/
• Website: https://selectpdf.com/
• Community Edition (free HTML to PDF converter, up to 5 pages): https://www.nuget.org/packages/SelectPdf.HtmlToPdf.Universal