C# PDF how-to guides, with code that runs.

Convert a password-protected web page to PDF in C# with SelectPdf.Universal: send a bearer token or session cookie, answer Basic auth, or fill in a login form.

Digitally sign a PDF in C# with a .pfx certificate and SelectPdf.Universal: a visible signature with reason and location, a seal image, and a second signer.

Make HTML to PDF in C# look the same on Windows and Linux with SelectPdf.Universal: built-in Liberation fonts, Noto fonts for every script, your own fonts.

Convert a page behind a login to PDF in C#

Convert a password-protected web page to PDF in C# with SelectPdf.Universal: send a bearer token or session cookie, answer Basic auth, or fill in a login form.

Free HTML to PDF in C# with the SelectPdf Community Edition

Convert HTML to PDF in C# for free with the SelectPdf Community Edition on Windows, Linux, macOS and Docker: setup, headers and footers, and the 5-page limit.

Generate an invoice PDF from an HTML template in C#

Generate invoice PDFs in C# from an HTML template and your data with SelectPdf.Universal: line items, totals, A4 margins, repeating table headers, page numbers.

Control page breaks in HTML to PDF with CSS

Control where pages break when you convert HTML to PDF in C#: page-break-before, page-break-after and page-break-inside in CSS, plus breaks from @media print.

HTML to PDF in C#: convert a URL or an HTML string

Convert a web page URL or an HTML string to PDF in C# on .NET 8 or .NET 10, with A4 pages and 20 mm margins, on Windows, Linux and macOS, step by step.

Add page numbers to a PDF in C# (Page X of Y)

Add "Page X of Y" page numbers to PDFs in C#: in an HTML to PDF footer, skipped on a cover page, or stamped onto an existing PDF with SelectPdf.Universal.

HTML headers and footers with a logo and the date in C#

Add an HTML header with a logo and title and a footer with the date to each PDF page in C#, from an HTML string, a URL or an image, with SelectPdf.Universal.

Convert HTML to PNG or JPG in C#

Convert a URL or an HTML string to a PNG or JPG image in C# with HtmlToImage: set the browser size, resolve relative images, capture one element, go async.

Take a full-page screenshot of a website in C#

Capture a whole web page as one PNG in C# with SelectPdf.Universal HtmlToImage: auto height, a first-screen crop, a phone-width capture and script delays.

Convert HTML to PDF asynchronously and in parallel in C#

Convert many pages to PDF at once in C#: async conversion with Task.WhenAll, a concurrency limit, timeouts and cancellation, batches with Parallel.ForEachAsync.

Generate PDFs in a background queue in .NET (BackgroundService)

Queue HTML and URL to PDF jobs in a .NET app and convert them in a BackgroundService: a Channel as the job queue, async conversion and a clean shutdown.

Add a watermark to every page of a PDF in C#

Stamp a rotated, semi-transparent CONFIDENTIAL watermark on every page of an existing PDF in C# with SelectPdf.Universal, plus logo and DRAFT variations.

Merge PDF files in C#: files, streams and folders

Merge PDF files in C# with SelectPdf.Universal: combine files, in-memory streams, converted HTML or a whole folder into one PDF, on Windows, Linux and macOS.

Fill PDF form fields in C#

Fill PDF form fields in C#: create a fillable form from HTML, set text boxes, check boxes, combo boxes and radio buttons by name, then save the filled PDF.

Flatten a PDF form in C#

Flatten a PDF form in C#: create a fillable form from HTML, fill it, and turn the values into page content, for all fields or some, or for an existing PDF file.

Digitally sign a PDF with a PFX certificate in C#

Digitally sign a PDF in C# with a .pfx certificate and SelectPdf.Universal: a visible signature with reason and location, a seal image, and a second signer.

Validate PDF digital signatures in C#

Validate PDF digital signatures in C# with SelectPdf.Universal: check they are intact and trusted, and detect tampering, later changes and revoked certificates.

Password-protect a PDF with AES-256 in C#

Encrypt a PDF with AES-256 in C#: set an open password, block printing and copying with an owner password, or protect an existing file with SelectPdf.Universal.

Redact PDF text with a regular expression in C#

Remove sensitive text such as card numbers from a PDF in C# with SelectPdf.Universal. The content is deleted from the file, not just covered over.

Accessible PDF/UA from HTML in C# (tagged PDF)

Create accessible, tagged PDF/UA-1 and PDF/UA-2 documents from HTML in C#, with PDF/A-4 or PDF/A-3A for archiving, all validated with veraPDF.

Convert HTML to PDF/A for archiving in C#

Convert HTML to archival PDF/A in C#: PDF/A-2b with metadata, PDF/A-1b, PDF/A-3b with an embedded source file, and merging into PDF/A, validated by veraPDF.

Create a ZUGFeRD / Factur-X invoice in C#

Create a ZUGFeRD / Factur-X hybrid invoice in C#: convert HTML to PDF/A-3 and embed the CII XML with AddZugferdInvoice and the right profile.

Create an XRechnung invoice in C#

Create an XRechnung invoice in C#: convert the invoice to PDF/A-3 and embed the XRechnung XML as xrechnung.xml with AddZugferdInvoice, validated by veraPDF.

Convert DOCX to PDF on Linux in C#

Convert Word DOCX files to PDF on Linux in C# with SelectPdf.Universal, and no Microsoft Office installed. Missing fonts come from the bundled Liberation fonts.

Convert Word documents to PDF/A for archiving in C#

Convert Word DOCX files to archival PDF/A in C#: PDF/A-2b with title metadata, PDF/A-4, accessible PDF/A-3a with PDF/UA-1, and merging into PDF/A.

Convert PDF pages to PNG images in C#

Render every page of a PDF to a PNG image in C# with SelectPdf.Universal at the resolution you choose, plus a first-page thumbnail, JPG files and grayscale.

Extract text from a PDF in C#

Extract the text of a PDF in C# with SelectPdf.Universal: get it as a string or save it to a UTF-8 file, read a page range, keep columns or reading order.

Generate and download a PDF from Blazor in C#

Generate a PDF on the server from a Blazor Web App in C# and download it with a link or a JS interop stream, using a Razor component as the template.

Return a PDF from an ASP.NET Core endpoint in C#

Return HTML rendered as a PDF download from an ASP.NET Core minimal API endpoint in C#, asynchronously, and render Razor components such as invoices to PDF.

Fonts on Linux: the same PDF on every server, in every language (C#)

Make HTML to PDF in C# look the same on Windows and Linux with SelectPdf.Universal: built-in Liberation fonts, Noto fonts for every script, your own fonts.

HTML to PDF on ARM64 Linux (AWS Graviton) in C#

Convert HTML to PDF in C# on ARM64 Linux, such as AWS Graviton, with SelectPdf.Universal: the linux-arm64 engine package and an ARM64 Docker image, no apt-get.

HTML to PDF on Google Cloud Run in C#

Convert HTML to PDF in an ASP.NET Core container on Google Cloud Run: packages and fonts, a Dockerfile with the non-root user, and the gcloud deploy settings.

HTML to PDF in AWS Lambda with C# (x86_64 and arm64)

Generate PDFs from HTML in an AWS Lambda function in C#, packaged as a container image on x86_64 or arm64 Graviton, with the Dockerfile and deployment steps.

HTML to PDF in Azure Functions with C#

Generate PDFs from HTML in an Azure Functions HTTP trigger with C#: the isolated worker, the plans that work, the Linux and Windows packages, deployment.

HTML to PDF in Docker on Linux with C# (no apt-get)

Convert HTML to PDF in a Linux Docker container with SelectPdf.Universal: two NuGet packages, a stock .NET runtime image, and no system packages to install.

HTML to PDF on Azure App Service (Linux) in C#

Convert HTML to PDF in an ASP.NET Core app on Azure App Service for Linux: which plan to use, the packages and fonts it needs, and zip deployment.

Fix HTML to PDF on Alpine Linux in C# with the remote engine

HTML to PDF fails on Alpine because the native engines need glibc. Convert from an Alpine .NET image in C# through the selectpdf/engine container instead.

Fix blank pages and missing content in HTML to PDF (C#)

Fix blank or incomplete PDFs from HTML in C#: wait for script content, start the conversion from JavaScript, resolve relative images and use print CSS.