Code Samples for C#/VB .NET Core

Using HTML To Create a PDF

using IronPdf;

// Disable local disk access or cross-origin requests
Installation.EnableWebSecurity = true;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Create a PDF from a HTML string using C#
var pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>");

// Export to a file or Stream
pdf.SaveAs("output.pdf");

// Advanced Example with HTML Assets
// Load external html assets: Images, CSS and JavaScript.
// An optional BasePath 'C:\site\assets\' is set as the file location to load assets from
var myAdvancedPdf = renderer.RenderHtmlAsPdf("<img src='icons/iron.png'>", @"C:\site\assets\");
myAdvancedPdf.SaveAs("html-with-assets.pdf");

Imports IronPdf

' Disable local disk access or cross-origin requests
Installation.EnableWebSecurity = True

' Instantiate Renderer
Dim renderer = New ChromePdfRenderer()

' Create a PDF from a HTML string using C#
Dim pdf = renderer.RenderHtmlAsPdf("<h1>Hello World</h1>")

' Export to a file or Stream
pdf.SaveAs("output.pdf")

' Advanced Example with HTML Assets
' Load external html assets: Images, CSS and JavaScript.
' An optional BasePath 'C:\site\assets\' is set as the file location to load assets from
Dim myAdvancedPdf = renderer.RenderHtmlAsPdf("<img src='icons/iron.png'>", "C:\site\assets\")
myAdvancedPdf.SaveAs("html-with-assets.pdf")

IronPDF allows developers to create PDF documents easily in C#, F#, and VB.NET for .NET Core and .NET Framework.

In this example we show that a PDF document can be rendered from any HTML. This allows us to create PDFs that closely match the branding of existing websites.

You can choose simple HTML like the above, or incorporate CSS, images and JavaScript.

This process also allows PDF design to be delegated to web designers, rather than be tasked to back-end coders.

IronPDF uses a pixel perfect Chrome rendering engine to turn your HTML5 with CSS3 and JavaScript support into PDF documents. This can take the form of strings, external files or external URLs, all of which can be rendered to PDF easily using IronPDF.

Converting a URL to a PDF

using IronPdf;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Create a PDF from a URL or local file path
var pdf = renderer.RenderUrlAsPdf("https://ironpdf.com/");

// Export to a file or Stream
pdf.SaveAs("url.pdf");

Imports IronPdf

' Instantiate Renderer
Private renderer = New ChromePdfRenderer()

' Create a PDF from a URL or local file path
Private pdf = renderer.RenderUrlAsPdf("https://ironpdf.com/")

' Export to a file or Stream
pdf.SaveAs("url.pdf")

IronPDF makes it very straightforward to render HTML from existing URLs as PDF documents. There is a very high level of support for JavaScript, Images, Forms and CSS.

Rendering PDFs from ASP.NET URLs which accept query string variables can make PDF development an easy collaboration between designers and coders.

Steps to Convert URL to PDF in C#

Download URL to PDF C# Library
Install with NuGet to Test the Library
Rendering PDFs from ASP.NET URLs which accept query string variables
Creating PDF Document from URL
View Your PDF Output document

PDF Generation Settings

using IronPdf;
using IronPdf.Engines.Chrome;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Many rendering options to use to customize!
renderer.RenderingOptions.SetCustomPaperSizeInInches(12.5, 20);
renderer.RenderingOptions.PrintHtmlBackgrounds = true;
renderer.RenderingOptions.PaperOrientation = IronPdf.Rendering.PdfPaperOrientation.Landscape;
renderer.RenderingOptions.Title = "My PDF Document Name";
renderer.RenderingOptions.EnableJavaScript = true;
renderer.RenderingOptions.WaitFor.RenderDelay(50); // in milliseconds
renderer.RenderingOptions.CssMediaType = IronPdf.Rendering.PdfCssMediaType.Screen;
renderer.RenderingOptions.FitToPaperMode = FitToPaperModes.Zoom;
renderer.RenderingOptions.Zoom = 100;
renderer.RenderingOptions.CreatePdfFormsFromHtml = true;

// Supports margin customization!
renderer.RenderingOptions.MarginTop = 40; //millimeters
renderer.RenderingOptions.MarginLeft = 20; //millimeters
renderer.RenderingOptions.MarginRight = 20; //millimeters
renderer.RenderingOptions.MarginBottom = 40; //millimeters

// Can set FirstPageNumber if you have a cover page
renderer.RenderingOptions.FirstPageNumber = 1; // use 2 if a cover page will be appended

// Settings have been set, we can render:
renderer.RenderHtmlFileAsPdf("assets/wikipedia.html").SaveAs("output/my-content.pdf");

IRON VB CONVERTER ERROR developers@ironsoftware.com

IronPDF aims to be as flexible as possible for the developer.

In this example, we show the balance between providing an API that automates internal functionality and providing one that gives you control.

IronPDF supports many customizations for generated PDF files, including: page sizing, page margins, header/footer content, content scaling, CSS rulesets, and JavaScript execution.

We want developers to be able to control how Chrome turns a web page into a PDF. The ChromePdfRenderer class makes this possible.

Examples of settings available on the ChromePDFRenderOptions class include settings for margins, headers, footers, paper size, and form creation.

HTML or Image File to PDF

using IronPdf;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Create a PDF from an existing HTML file using C#
var pdf = renderer.RenderHtmlFileAsPdf("example.html");

// Export to a file or Stream
pdf.SaveAs("output.pdf");

Imports IronPdf

' Instantiate Renderer
Private renderer = New ChromePdfRenderer()

' Create a PDF from an existing HTML file using C#
Private pdf = renderer.RenderHtmlFileAsPdf("example.html")

' Export to a file or Stream
pdf.SaveAs("output.pdf")

One of the easiest ways to use IronPDF is to tell it to render an HTML file.

IronPDF can render any HTML file saved on a machine.

In this example, we show that all relative assets such as CSS, images and JavaScript will be rendered as if the file had been opened using the file:// protocol.

This method has the advantage of allowing the developer the opportunity to test the HTML content in a browser during development. They can, in particular, test the fidelity in rendering. We recommend Chrome, as it is the web browser on which IronPDF's rendering engine is based.

If it looks right in Chrome, then it will be pixel-perfect in IronPDF as well.

ASPX To PDF Settings

using IronPdf;

var PdfOptions = new IronPdf.ChromePdfRenderOptions()
{
    CreatePdfFormsFromHtml = true,
    EnableJavaScript = false,
    Title = "My ASPX Page Rendered as a PDF"
    //.. many more options available
};

AspxToPdf.RenderThisPageAsPdf(AspxToPdf.FileBehavior.Attachment, "MyPdfFile.pdf", PdfOptions);

Imports IronPdf

Private PdfOptions = New IronPdf.ChromePdfRenderOptions() With {
	.CreatePdfFormsFromHtml = True,
	.EnableJavaScript = False,
	.Title = "My ASPX Page Rendered as a PDF"
}

AspxToPdf.RenderThisPageAsPdf(AspxToPdf.FileBehavior.Attachment, "MyPdfFile.pdf", PdfOptions)

This example demonstrates how the user can change PDF print options to turn form into HTML.

IronPDF's ASPX to PDF functionality has many options available for rendering HTML to PDF from a string or a file.

Two options of particular importance are:

Allowing developers to specify if HTML forms should be rendered as interactive PDF forms during conversion.
Allowing developers to specify if the PDF should be displayed "in browser," or as a file download.

Image To PDF

using IronPdf;
using System.IO;
using System.Linq;

// One or more images as IEnumerable. This example selects all JPEG images in a specific 'assets' folder.
var imageFiles = Directory.EnumerateFiles("assets").Where(f => f.EndsWith(".jpg") || f.EndsWith(".jpeg"));

// Converts the images to a PDF and save it.
ImageToPdfConverter.ImageToPdf(imageFiles).SaveAs("composite.pdf");

// Also see PdfDocument.RasterizeToImageFiles() method to flatten a PDF to images or thumbnails

Imports IronPdf
Imports System.IO
Imports System.Linq

' One or more images as IEnumerable. This example selects all JPEG images in a specific 'assets' folder.
Private imageFiles = Directory.EnumerateFiles("assets").Where(Function(f) f.EndsWith(".jpg") OrElse f.EndsWith(".jpeg"))

' Converts the images to a PDF and save it.
ImageToPdfConverter.ImageToPdf(imageFiles).SaveAs("composite.pdf")

' Also see PdfDocument.RasterizeToImageFiles() method to flatten a PDF to images or thumbnails

Construct a PDF from one or more image files using the IronPdf.ImageToPdfConverter class.

How to Convert an Image to a PDF in C#

Given a single image located on a computer at C:\images\example.png, we can convert it quickly into a PDF document by calling the IronPdf.ImageToPdfConverter.ImageToPdf method with its file path:

IronPdf.ImageToPdfConverter.ImageToPdf(@"C:\images\example.png").SaveAs("example.pdf");

IronPdf.ImageToPdfConverter.ImageToPdf(@"C:\images\example.png").SaveAs("example.pdf");

IronPdf.ImageToPdfConverter.ImageToPdf("C:\images\example.png").SaveAs("example.pdf")

VB C#

Combine Multiple Images Into a PDF File

We can also convert images to PDFs in batch into a single PDF document using System.IO.Directory.EnumerateFiles along with ImageToPdfConverter.ImageToPdf:

string sourceDirectory = "D:\web\assets";
string destinationFile = "JpgToPDF.pdf";
var imageFiles = Directory.EnumerateFiles(sourceDirectory, "*.jpg");
ImageToPdfConverter.ImageToPdf(imageFiles).SaveAs(destinationFile);

string sourceDirectory = "D:\web\assets";
string destinationFile = "JpgToPDF.pdf";
var imageFiles = Directory.EnumerateFiles(sourceDirectory, "*.jpg");
ImageToPdfConverter.ImageToPdf(imageFiles).SaveAs(destinationFile);

Dim sourceDirectory As String = "D:\web" & ChrW(7) & "ssets"
Dim destinationFile As String = "JpgToPDF.pdf"
Dim imageFiles = Directory.EnumerateFiles(sourceDirectory, "*.jpg")
ImageToPdfConverter.ImageToPdf(imageFiles).SaveAs(destinationFile)

VB C#

Headers & Footers

using IronPdf;

// Initiate PDF Renderer
var renderer = new ChromePdfRenderer();

// Add a header to every page easily
renderer.RenderingOptions.FirstPageNumber = 1; // use 2 if a cover page  will be appended
renderer.RenderingOptions.TextHeader.DrawDividerLine = true;
renderer.RenderingOptions.TextHeader.CenterText = "{url}";
renderer.RenderingOptions.TextHeader.Font = IronSoftware.Drawing.FontTypes.Helvetica;
renderer.RenderingOptions.TextHeader.FontSize = 12;
renderer.RenderingOptions.MarginTop = 25; //create 25mm space for header

// Add a footer too
renderer.RenderingOptions.TextFooter.DrawDividerLine = true;
renderer.RenderingOptions.TextFooter.Font = IronSoftware.Drawing.FontTypes.Arial;
renderer.RenderingOptions.TextFooter.FontSize = 10;
renderer.RenderingOptions.TextFooter.LeftText = "{date} {time}";
renderer.RenderingOptions.TextFooter.RightText = "{page} of {total-pages}";
renderer.RenderingOptions.MarginTop = 25; //create 25mm space for footer

// Mergeable fields are:
// {page} {total-pages} {url} {date} {time} {html-title} & {pdf-title}

Imports IronPdf

' Initiate PDF Renderer
Private renderer = New ChromePdfRenderer()

' Add a header to every page easily
renderer.RenderingOptions.FirstPageNumber = 1 ' use 2 if a cover page  will be appended
renderer.RenderingOptions.TextHeader.DrawDividerLine = True
renderer.RenderingOptions.TextHeader.CenterText = "{url}"
renderer.RenderingOptions.TextHeader.Font = IronSoftware.Drawing.FontTypes.Helvetica
renderer.RenderingOptions.TextHeader.FontSize = 12
renderer.RenderingOptions.MarginTop = 25 'create 25mm space for header

' Add a footer too
renderer.RenderingOptions.TextFooter.DrawDividerLine = True
renderer.RenderingOptions.TextFooter.Font = IronSoftware.Drawing.FontTypes.Arial
renderer.RenderingOptions.TextFooter.FontSize = 10
renderer.RenderingOptions.TextFooter.LeftText = "{date} {time}"
renderer.RenderingOptions.TextFooter.RightText = "{page} of {total-pages}"
renderer.RenderingOptions.MarginTop = 25 'create 25mm space for footer

' Mergeable fields are:
' {page} {total-pages} {url} {date} {time} {html-title} & {pdf-title}

Headers and Footers may be added to PDF documents in two distinct ways.

Classic text headers and footers, which allows text-based headers to be added, with the option to merge in dynamic data.
HTML headers and footers, which allows the developer to render HTML headers and footers to PDF files, also allowing the templating of dynamic data. This method is more flexible, although it is harder to use.

The class TextHeaderFooter in IronPDF defines PDF headers and footers display options. This uses a logical approach to rendering headers and footers for the most common use cases.

In this example, we show you how to add classic text headers and footers to your PDF documents in IronPDF.

When adding headers and footers to your document, you have the option to set the headers text to be centered on the PDF document. You can also merge metadata into your header using placeholder strings. You can find these strings here. You can also add a horizontal line divider between the headers or footers and the page content on every page of the PDF document, influence font and font sizes etc. It is a very useful feature that ticks all the boxes.

HTML Headers & Footers

using IronPdf;
using System;

// Instantiate Renderer
var renderer = new IronPdf.ChromePdfRenderer();


// Build a footer using html to style the text
// mergeable 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
};

// Use sufficient MarginBottom to ensure that the HtmlFooter does not overlap with the main PDF page content.
renderer.RenderingOptions.MarginBottom = 25; //mm


// Build a header using an image asset
// Note the use of BaseUrl to set a relative path to the assets
renderer.RenderingOptions.HtmlHeader = new HtmlHeaderFooter()
{
    MaxHeight = 20, //millimeters
    HtmlFragment = "<img src='logo.png'>",
    BaseUrl = new Uri(@"C:\assets\images\").AbsoluteUri
};

// Use sufficient MarginTop to ensure that the HtmlHeader does not overlap with the main PDF page content.
renderer.RenderingOptions.MarginTop = 25; //mm

Imports IronPdf
Imports System

' Instantiate Renderer
Private renderer = New IronPdf.ChromePdfRenderer()


' Build a footer using html to style the text
' mergeable fields are:
' {page} {total-pages} {url} {date} {time} {html-title} & {pdf-title}
renderer.RenderingOptions.HtmlFooter = New HtmlHeaderFooter() With {
	.MaxHeight = 15,
	.HtmlFragment = "<center><i>{page} of {total-pages}<i></center>",
	.DrawDividerLine = True
}

' Use sufficient MarginBottom to ensure that the HtmlFooter does not overlap with the main PDF page content.
renderer.RenderingOptions.MarginBottom = 25 'mm


' Build a header using an image asset
' Note the use of BaseUrl to set a relative path to the assets
renderer.RenderingOptions.HtmlHeader = New HtmlHeaderFooter() With {
	.MaxHeight = 20,
	.HtmlFragment = "<img src='logo.png'>",
	.BaseUrl = (New Uri("C:\assets\images\")).AbsoluteUri
}

' Use sufficient MarginTop to ensure that the HtmlHeader does not overlap with the main PDF page content.
renderer.RenderingOptions.MarginTop = 25 'mm

The HTML headers and footers are rendered as independent HTML documents which may have their own assets and stylesheets. It gives developers total control over how their headers and footers look. The height of the rendered headers or footers can be controlled to match their content exactly.

In this example, we show how to add HTML headers and footers to your PDF documents in IronPDF.

HTML headers or footers will be printed onto every page of the PDF when you add them to your project. This can be used to override classic headers and footers.

When using HtmlHeaderFooter, it is important to set HtmlFragment, which will be used to render the headers or footers. It should be an HTML snippet rather than a complete document. It may also contain styles & images.

You can also merge meta-data into your HTML using any of these placeholder strings such as {page} {total-pages} {url} {date} {time} {html-title} {pdf-title}.

Form Data

using IronPdf;
using System;

// Step 1.  Creating a PDF with editable forms from HTML using form and input tags
// Radio Button and Checkbox can also be implemented with input type 'radio' and 'checkbox'
const string formHtml = @"
    <html>
        <body>
            <h2>Editable PDF  Form</h2>
            <form>
              First name: <br> <input type='text' name='firstname' value=''> <br>
              Last name: <br> <input type='text' name='lastname' value=''> <br>
              <br>
              <p>Please specify your gender:</p>
              <input type='radio' id='female' name='gender' value= 'Female'>
                <label for='female'>Female</label> <br>
                <br>
              <input type='radio' id='male' name='gender' value='Male'>
                <label for='male'>Male</label> <br>
                <br>
              <input type='radio' id='non-binary/other' name='gender' value='Non-Binary / Other'>
                <label for='non-binary/other'>Non-Binary / Other</label>
              <br>

              <p>Please select all medical conditions that apply:</p>
              <input type='checkbox' id='condition1' name='Hypertension' value='Hypertension'>
              <label for='condition1'> Hypertension</label><br>
              <input type='checkbox' id='condition2' name='Heart Disease' value='Heart Disease'>
              <label for='condition2'> Heart Disease</label><br>
              <input type='checkbox' id='condition3' name='Stoke' value='Stoke'>
              <label for='condition3'> Stoke</label><br>
              <input type='checkbox' id='condition4' name='Diabetes' value='Diabetes'>
              <label for='condition4'> Diabetes</label><br>
              <input type='checkbox' id='condition5' name='Kidney Disease' value='Kidney Disease'>
              <label for='condition5'> Kidney Disease</label><br>
            </form>
        </body>
    </html>";

// Instantiate Renderer
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.CreatePdfFormsFromHtml = true;
renderer.RenderHtmlAsPdf(formHtml).SaveAs("BasicForm.pdf");

// Step 2. Reading and Writing PDF form values.
var FormDocument = PdfDocument.FromFile("BasicForm.pdf");

// Set and Read the value of the "firstname" field
var FirstNameField = FormDocument.Form.FindFormField("firstname");
FirstNameField.Value = "Minnie";
Console.WriteLine("FirstNameField value: {0}", FirstNameField.Value);

// Set and Read the value of the "lastname" field
var LastNameField = FormDocument.Form.FindFormField("lastname");
LastNameField.Value = "Mouse";
Console.WriteLine("LastNameField value: {0}", LastNameField.Value);

FormDocument.SaveAs("FilledForm.pdf");

Imports IronPdf
Imports System

' Step 1.  Creating a PDF with editable forms from HTML using form and input tags
' Radio Button and Checkbox can also be implemented with input type 'radio' and 'checkbox'
Private Const formHtml As String = "
    <html>
        <body>
            <h2>Editable PDF  Form</h2>
            <form>
              First name: <br> <input type='text' name='firstname' value=''> <br>
              Last name: <br> <input type='text' name='lastname' value=''> <br>
              <br>
              <p>Please specify your gender:</p>
              <input type='radio' id='female' name='gender' value= 'Female'>
                <label for='female'>Female</label> <br>
                <br>
              <input type='radio' id='male' name='gender' value='Male'>
                <label for='male'>Male</label> <br>
                <br>
              <input type='radio' id='non-binary/other' name='gender' value='Non-Binary / Other'>
                <label for='non-binary/other'>Non-Binary / Other</label>
              <br>

              <p>Please select all medical conditions that apply:</p>
              <input type='checkbox' id='condition1' name='Hypertension' value='Hypertension'>
              <label for='condition1'> Hypertension</label><br>
              <input type='checkbox' id='condition2' name='Heart Disease' value='Heart Disease'>
              <label for='condition2'> Heart Disease</label><br>
              <input type='checkbox' id='condition3' name='Stoke' value='Stoke'>
              <label for='condition3'> Stoke</label><br>
              <input type='checkbox' id='condition4' name='Diabetes' value='Diabetes'>
              <label for='condition4'> Diabetes</label><br>
              <input type='checkbox' id='condition5' name='Kidney Disease' value='Kidney Disease'>
              <label for='condition5'> Kidney Disease</label><br>
            </form>
        </body>
    </html>"

' Instantiate Renderer
Private renderer = New ChromePdfRenderer()
renderer.RenderingOptions.CreatePdfFormsFromHtml = True
renderer.RenderHtmlAsPdf(formHtml).SaveAs("BasicForm.pdf")

' Step 2. Reading and Writing PDF form values.
Dim FormDocument = PdfDocument.FromFile("BasicForm.pdf")

' Set and Read the value of the "firstname" field
Dim FirstNameField = FormDocument.Form.FindFormField("firstname")
FirstNameField.Value = "Minnie"
Console.WriteLine("FirstNameField value: {0}", FirstNameField.Value)

' Set and Read the value of the "lastname" field
Dim LastNameField = FormDocument.Form.FindFormField("lastname")
LastNameField.Value = "Mouse"
Console.WriteLine("LastNameField value: {0}", LastNameField.Value)

FormDocument.SaveAs("FilledForm.pdf")

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You can create editable PDF documents with IronPDF as easily as a normal document. The PdfForm class is a collection of user-editable form fields within a PDF document. It can be implemented into your PDF render to make it a form or an editable document.

This example shows you how to create editable PDF forms in IronPDF.

PDFs with editable forms can be created from HTML simply by adding <form>, <input>, and <textarea> tags to the document parts.

The PdfDocument.Form.GetFieldByName can be used to read and write the value of any form field. The field's name will be the same as the 'name' attribute given to that field in your HTML.

The PdfDocument.Form object can be used in two ways.

The first is to populate the default value of form fields, which must be focused in Adobe Reader to display this value.
The second is to read data from user-filled PDF forms in any language.

Rasterize a PDF to Images

using IronPdf;
using IronSoftware.Drawing;

var pdf = PdfDocument.FromFile("Example.pdf");

// Extract all pages to a folder as image files
pdf.RasterizeToImageFiles(@"C:\image\folder\*.png");

// Dimensions and page ranges may be specified
pdf.RasterizeToImageFiles(@"C:\image\folder\example_pdf_image_*.jpg", 100, 80);

// Extract all pages as AnyBitmap objects
AnyBitmap[] pdfBitmaps = pdf.ToBitmap();

Imports IronPdf
Imports IronSoftware.Drawing

Private pdf = PdfDocument.FromFile("Example.pdf")

' Extract all pages to a folder as image files
pdf.RasterizeToImageFiles("C:\image\folder\*.png")

' Dimensions and page ranges may be specified
pdf.RasterizeToImageFiles("C:\image\folder\example_pdf_image_*.jpg", 100, 80)

' Extract all pages as AnyBitmap objects
Dim pdfBitmaps() As AnyBitmap = pdf.ToBitmap()

Use IronPDF to convert a PDF to images in your preferred file type, image dimensions, and DPI quality.

To convert a PDF document to images, call IronPDF's RasterizeToImageFiles method on a PdfDocument object. A PDF document can be loaded using the PdfDocument.FromFile method or one of the available PDF generation methods.

RasterizeToImageFiles renders each page of the as a rasterized image. The first argument specifies the naming pattern to use for each image. Optional arguments can be used to customize the quality and dimensions for each image. Another one causes the method to convert selected pages from the PDF into images.

Line 24 of the featured code example demonstrates the ToBitMap method. Call this method on any PdfDocument object to quickly convert the PDF into AnyBitmap objects that can be saved to files or manipulated as needed.

How to Convert a PDF to Images in C#

Install the PDF to image C# library
Import existing PDF file with FromFile method
Convert PDF to image using RasterizeToImageFiles method
Specify save directory and image size
Check the output images

Editing PDFs

using IronPdf;
using System.Collections.Generic;

// Instantiate Renderer
var renderer = new ChromePdfRenderer();

// Join Multiple Existing PDFs into a single document
var pdfs = new List<PdfDocument>();
pdfs.Add(PdfDocument.FromFile("A.pdf"));
pdfs.Add(PdfDocument.FromFile("B.pdf"));
pdfs.Add(PdfDocument.FromFile("C.pdf"));
var pdf = PdfDocument.Merge(pdfs);
pdf.SaveAs("merged.pdf");

// Add a cover page
pdf.PrependPdf(renderer.RenderHtmlAsPdf("<h1>Cover Page</h1><hr>"));

// Remove the last page from the PDF and save again
pdf.RemovePage(pdf.PageCount - 1);
pdf.SaveAs("merged.pdf");

// Copy pages 5-7 and save them as a new document.
pdf.CopyPages(4, 6).SaveAs("excerpt.pdf");

foreach (var eachPdf in pdfs)
{
    eachPdf.Dispose();
}

Imports IronPdf
Imports System.Collections.Generic

' Instantiate Renderer
Private renderer = New ChromePdfRenderer()

' Join Multiple Existing PDFs into a single document
Private pdfs = New List(Of PdfDocument)()
pdfs.Add(PdfDocument.FromFile("A.pdf"))
pdfs.Add(PdfDocument.FromFile("B.pdf"))
pdfs.Add(PdfDocument.FromFile("C.pdf"))
Dim pdf = PdfDocument.Merge(pdfs)
pdf.SaveAs("merged.pdf")

' Add a cover page
pdf.PrependPdf(renderer.RenderHtmlAsPdf("<h1>Cover Page</h1><hr>"))

' Remove the last page from the PDF and save again
pdf.RemovePage(pdf.PageCount - 1)
pdf.SaveAs("merged.pdf")

' Copy pages 5-7 and save them as a new document.
pdf.CopyPages(4, 6).SaveAs("excerpt.pdf")

For Each eachPdf In pdfs
	eachPdf.Dispose()
Next eachPdf

IronPDF offers 50+ features for reading and editing PDFs. The most popular are merging, cloning and extracting pages.

IronPDF also allows its users to add watermarks, rotate pages, add annotations, digitally sign PDF pages, create PDF new documents, attach cover pages, customize PDF sizes, and much more when generating and formatting PDF files. Moreover, it supports conversion of PDFs into all conventional image file types, including JPG, BMP, JPEG, GIF, PNG, TIFF, etc.

Read this article to learn how to make full use of IronPDF to modify PDF documents to best suit project requirements.

How to Edit PDF files in C#

Install the C# library that can edit PDF files
Utilize `FromFile` method to import multiple PDF files
Access and modify PDF file using intuitive APIs in C#
Save the updated version as a new PDF using C#
View the newly edited PDF document

Passwords, Security & Metadata

using IronPdf;

// Open an Encrypted File, alternatively create a new PDF from Html
var pdf = PdfDocument.FromFile("encrypted.pdf", "password");

// Get file metadata
System.Collections.Generic.List<string> metadatakeys = pdf.MetaData.Keys(); // returns {"Title", "Creator", ...}

// Remove file metadata
pdf.MetaData.RemoveMetaDataKey("Title");
metadatakeys = pdf.MetaData.Keys(); // return {"Creator", ...} // title was deleted

// Edit file metadata
pdf.MetaData.Author = "Satoshi Nakamoto";
pdf.MetaData.Keywords = "SEO, Friendly";
pdf.MetaData.ModifiedDate = System.DateTime.Now;

// The following code makes a PDF read only and will disallow copy & paste and printing
pdf.SecuritySettings.RemovePasswordsAndEncryption();
pdf.SecuritySettings.MakePdfDocumentReadOnly("secret-key");
pdf.SecuritySettings.AllowUserAnnotations = false;
pdf.SecuritySettings.AllowUserCopyPasteContent = false;
pdf.SecuritySettings.AllowUserFormData = false;
pdf.SecuritySettings.AllowUserPrinting = IronPdf.Security.PdfPrintSecurity.FullPrintRights;

// Change or set the document encryption password
pdf.SecuritySettings.OwnerPassword = "top-secret"; // password to edit the pdf
pdf.SecuritySettings.UserPassword = "sharable"; // password to open the pdf
pdf.SaveAs("secured.pdf");

Imports System
Imports IronPdf

' Open an Encrypted File, alternatively create a new PDF from Html
Private pdf = PdfDocument.FromFile("encrypted.pdf", "password")

' Get file metadata
Private metadatakeys As System.Collections.Generic.List(Of String) = pdf.MetaData.Keys() ' returns {"Title", "Creator", ...}

' Remove file metadata
pdf.MetaData.RemoveMetaDataKey("Title")
metadatakeys = pdf.MetaData.Keys() ' return {"Creator", ...} // title was deleted

' Edit file metadata
pdf.MetaData.Author = "Satoshi Nakamoto"
pdf.MetaData.Keywords = "SEO, Friendly"
pdf.MetaData.ModifiedDate = DateTime.Now

' The following code makes a PDF read only and will disallow copy & paste and printing
pdf.SecuritySettings.RemovePasswordsAndEncryption()
pdf.SecuritySettings.MakePdfDocumentReadOnly("secret-key")
pdf.SecuritySettings.AllowUserAnnotations = False
pdf.SecuritySettings.AllowUserCopyPasteContent = False
pdf.SecuritySettings.AllowUserFormData = False
pdf.SecuritySettings.AllowUserPrinting = IronPdf.Security.PdfPrintSecurity.FullPrintRights

' Change or set the document encryption password
pdf.SecuritySettings.OwnerPassword = "top-secret" ' password to edit the pdf
pdf.SecuritySettings.UserPassword = "sharable" ' password to open the pdf
pdf.SaveAs("secured.pdf")

Granular meta-data and security settings can be applied. This now includes the ability to limit PDF documents to be unprintable, read only and encrypted. 128 bit encryption, decryption and password protection of PDF documents is supported.

PDF Watermarking

using IronPdf;

// Stamps a Watermark onto a new or existing PDF
var renderer = new ChromePdfRenderer();

var pdf = renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf");
pdf.ApplyWatermark("<h2 style='color:red'>SAMPLE</h2>", 30, IronPdf.Editing.VerticalAlignment.Middle, IronPdf.Editing.HorizontalAlignment.Center);
pdf.SaveAs(@"C:\Path\To\Watermarked.pdf");

Imports IronPdf

' Stamps a Watermark onto a new or existing PDF
Private renderer = New ChromePdfRenderer()

Private pdf = renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf")
pdf.ApplyWatermark("<h2 style='color:red'>SAMPLE</h2>", 30, IronPdf.Editing.VerticalAlignment.Middle, IronPdf.Editing.HorizontalAlignment.Center)
pdf.SaveAs("C:\Path\To\Watermarked.pdf")

IronPDF provides methods to 'watermark' PDF documents with HTML.

Using the ApplyStamp method, developers can add an HTML-based watermark to a PDF file. As shown in the example above, the HTML code for the watermark goes as the first argument to the method. Additional arguments to ApplyStamp control the rotation, opacity, and position of the watermark.

Utilize the ApplyStamp method in lieu of the ApplyWatermark method for more granular control over watermark placement. For example, use ApplyStamp to:

Add Text, Image, or HTML watermarks to PDFs
Apply the same watermark to every page of the PDF
Apply different watermarks to specific PDF pages
Adjust the placement of watermarks in front or behind page copy
Adjust the opacity, rotation and alignment of watermarks with more precision

How to Add Watermarks to PDF Files in C#

Download and install the IronPDF library.
Create a new PdfDocument or use an existing PdfDocument file.
Call the ApplyWatermark method to add watermarks to the PDF.
Export the PDF file by calling SaveAs.

Backgrounds & Foregrounds

using IronPdf;

// With IronPDF, we can easily merge 2 PDF files using one as a background or foreground
var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf");
pdf.AddBackgroundPdf(@"MyBackground.pdf");
pdf.AddForegroundOverlayPdfToPage(0, @"MyForeground.pdf", 0);
pdf.SaveAs(@"C:\Path\To\Complete.pdf");

Imports IronPdf

' With IronPDF, we can easily merge 2 PDF files using one as a background or foreground
Private renderer = New ChromePdfRenderer()
Private pdf = renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf")
pdf.AddBackgroundPdf("MyBackground.pdf")
pdf.AddForegroundOverlayPdfToPage(0, "MyForeground.pdf", 0)
pdf.SaveAs("C:\Path\To\Complete.pdf")

You may want to use a specific background and foreground as you create and render your PDF documents in IronPDF. In such a case, you can use an existing or rendered PDF as the background or foreground for another PDF document. This is particularly useful for design consistency and templating.

This example shows you how to use a PDF document as the background or foreground of another PDF document.

You can do this in C# by loading or creating a multi-page PDF as an IronPdf.PdfDocument object.

You can add backgrounds using PdfDocument.AddBackgroundPdf. There are several background insertion methods and overrides in the IronPdf.PdfDocument documentation. This adds a background to each page of your working PDF. The background is copied from a page in another PDF document.

You can add foregrounds, also known as "Overlays," using PdfDocument.AddForegroundOverlayPdfToPage. There are several foreground insertion methods and overrides in the IronPdf.PdfDocument documentation.

Support For .NET Core Coders

Regardless of whether its technical or sales inquiries, the Iron Team are close by to help with the majority of your questions. Connect with Iron to benefit as much as possible from our library in your project.

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C# & VB HTML-to-PDF Library for .NET Core

IronPDF utilizes a Chromium renderer for .NET Chromium to convert HTML files to PDF documents. There's no need for APIs to position or layout PDFs: IronPDF uses standard HTML, ASPX, JS, CSS and Images.

See Tutorials

Read PDF Text

IronPDF enables you to extract all embedded text content from PDFs to pass into your C# & .NET Core APPs. Import content from PDF archives into your business process systems.

Full API Reference

Edit PDFs in .NET Core

From Appending, converging, parting, and altering PDFs, utilize your own coding skills to precisely to get the correct PDF every time. IronPDF puts the development capabilities specifically into your hands, inside your C#/VB .NET Core Project.

Read Our Docs

Convert HTML5, JS, CSS and Image files to PDF documents using .NET Code.

Supports Your Document Types

Point IronPDF .NET Core Library at your HTML file, string or URL to simply convert to PDF. This uses your current documents and website pages to render your information to a PDF file.

For ASP .NET Core, C#, VB, MVC, ASPX, .NET

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Visual Studio Library for PDF Creation and Content Editing.

Get Going Fast with Microsoft Visual Studio

IronPDF puts PDF creation and editing control in your very own hands, rapidly with complete intellisense support and a Visual Studio installer. Use NuGet for Visual Studio or download the DLL. You'll be set up in a matter of moments. Only one DLL.

PM > Install-Package IronPdf Download DLL

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