How to Use the Rendering Options

Chaknith Bin

Updated:July 28, 2025

Rendering options in PDF generation refer to the settings and configurations that determine how a PDF document is created, displayed, and printed. These options can include a wide range of settings, such as rendering form field elements, enabling JavaScript, generating a table of contents, adding headers and footers, adjusting margins, setting PDF paper size, and more.

The ChromePdfRenderer class in IronPDF provides various rendering options that allow users to customize how PDFs are generated. It includes PaperFit, a manager that controls how content is laid out on PDF pages, offering different layout styles such as responsive CSS3 layouts or continuous feed.

Customize PDF output with rich RenderingOptions in one line!

new IronPdf.ChromePdfRenderer { RenderingOptions = { PrintHtmlBackgrounds = true, MarginTop = 0, MarginBottom = 0, CssMediaType = IronPdf.Rendering.PdfCssMediaType.Print, HtmlHeader = new IronPdf.HtmlHeaderFooter { HtmlFragment = "<div>My Header</div>" }, Language = "en-US", Timeout = 120000 } }
    .RenderHtmlStringAsPdf("<h1>Hello Options</h1>")
    .SaveAs("renderingOptions.pdf");

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First Step:

How to Use the Rendering Options

Download the C# library to use rendering options
Prepare the HTML assets or file to be converted into a PDF document
Instantiate the ChromePdfRenderer class to render the PDF
Access the RenderingOptions property directly to configure your settings
Render the PDF in the desired format

Rendering Options Example

Despite many rendering option properties being specifically designed for HTML-to-PDF conversion, they can also be used in other types of PDF conversions. Let's render Markdown syntax to PDF and use the rendering options to configure the PDF output.

:path=/static-assets/pdf/content-code-examples/how-to/rendering-options-render.cs

using IronPdf;

// Instantiate a ChromePdfRenderer object, which uses a headless version of the Chrome browser
// to render HTML/CSS as a PDF document.
ChromePdfRenderer renderer = new ChromePdfRenderer();

// Configure rendering options
// Enable printing of HTML backgrounds to ensure all styles are visible.
renderer.RenderingOptions.PrintHtmlBackgrounds = true;

// Set HTML header content using HtmlHeaderFooter.
renderer.RenderingOptions.HtmlHeader = new HtmlHeaderFooter
{
    // HTML fragment to add a header at the top of every page in the PDF.
    HtmlFragment = "<h1>Header Content</h1>"
};

// Set a custom paper size for the PDF in millimeters (width and height).
renderer.RenderingOptions.SetCustomPaperSizeinMilimeters(150, 150);

// Set the top margin to zero to start the content from the very top of the page.
renderer.RenderingOptions.MarginTop = 0;

// Define a Markdown string that will be rendered as a PDF.
// Markdown text allows basic formatting like bold and italic styles.
string md = "This is some **bold** and *italic* text.";

// Render the Markdown string to a PDF document.
// The library will convert Markdown syntax into equivalent HTML before rendering it as a PDF.
PdfDocument pdf = renderer.RenderMarkdownStringAsPdf(md);

// Save the generated PDF to a file named "renderingOptions.pdf."
pdf.SaveAs("renderingOptions.pdf");

Imports IronPdf

' Instantiate a ChromePdfRenderer object, which uses a headless version of the Chrome browser
' to render HTML/CSS as a PDF document.
Private renderer As New ChromePdfRenderer()

' Configure rendering options
' Enable printing of HTML backgrounds to ensure all styles are visible.
renderer.RenderingOptions.PrintHtmlBackgrounds = True

' Set HTML header content using HtmlHeaderFooter.
renderer.RenderingOptions.HtmlHeader = New HtmlHeaderFooter With {.HtmlFragment = "<h1>Header Content</h1>"}

' Set a custom paper size for the PDF in millimeters (width and height).
renderer.RenderingOptions.SetCustomPaperSizeinMilimeters(150, 150)

' Set the top margin to zero to start the content from the very top of the page.
renderer.RenderingOptions.MarginTop = 0

' Define a Markdown string that will be rendered as a PDF.
' Markdown text allows basic formatting like bold and italic styles.
Dim md As String = "This is some **bold** and *italic* text."

' Render the Markdown string to a PDF document.
' The library will convert Markdown syntax into equivalent HTML before rendering it as a PDF.
Dim pdf As PdfDocument = renderer.RenderMarkdownStringAsPdf(md)

' Save the generated PDF to a file named "renderingOptions.pdf."
pdf.SaveAs("renderingOptions.pdf")

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All Rendering Options

We have some advanced options that define PDF-rendering options like adjusting margins, paper orientation, paper size, and more.

Below is a table to illustrate the many different options.

Class	ChromePdfRenderer
Description	Used to define PDF printout options, like paper size, DPI, headers, and footers
Properties / functions	Type	Description
CustomCookies	Dictionary	Custom cookies for the HTML render. Cookies do not persist between renders and must be set each time.
PaperFit	VirtualPaperLayoutManager	A manager for setting up virtual paper layouts, controlling how content will be laid out on PDF "paper" pages. Includes options for Default Chrome Behavior, Zoomed, Responsive CSS3 Layouts, Scale-To-Page & Continuous Feed style PDF page setups.
UseMarginsOnHeaderAndFooter	UseMargins	Use margin values from the main document when rendering headers and footers.
CreatePdfFormsFromHtml	bool	Turns all HTML form elements into editable PDF forms. Default value is true.
CssMediaType	PdfCssMediaType	Enables Media="screen" CSS Styles and StyleSheets. Default value is PdfCssMediaType.Screen.
CustomCssUrl	string	Allows a custom CSS style-sheet to be applied to HTML before rendering. May be a local file path or a remote URL. Only applicable when rendering HTML to PDF.
EnableJavaScript	bool	Enables JavaScript and JSON to be executed before the page is rendered. Ideal for printing from Ajax / Angular Applications. Default value is false.
EnableMathematicalLaTex	bool	Enables rendering of Mathematical LaTeX Elements.
Javascript	string	A custom JavaScript string to be executed after all HTML has loaded but before PDF rendering.
JavascriptMessageListener	StringDelegate	A method callback to be invoked whenever a browser JavaScript console message becomes available.
FirstPageNumber	int	First page number to be used in PDF Headers and Footers. Default value is 1.
TableOfContents	TableOfContentsTypes	Generates a table of contents at the location in the HTML document where an element is found with id "ironpdf-toc".
GrayScale	bool	Outputs a black-and-white PDF. Default value is false.
TextHeader	ITextHeaderFooter	Sets the footer content for every PDF page as text, supporting 'mail-merge' and automatically turning URLs into hyperlinks.
TextFooter	ITextHeaderFooter
HtmlHeader	HtmlHeaderFooter	Sets the header content for every PDF page as HTML. Supports 'mail-merge'.
HtmlFooter	HtmlHeaderFooter
InputEncoding	Encoding	The input character encoding as a string. Default value is Encoding.UTF8.
MarginTop	double	Top PDF "paper" margin in millimeters. Set to zero for border-less and commercial printing applications. Default value is 25.
MarginRight	double	Right PDF "paper" margin in millimeters. Set to zero for border-less and commercial printing applications. Default value is 25.
MarginBottom	double	Bottom PDF "paper" margin in millimeters. Set to zero for border-less and commercial printing applications. Default value is 25.
MarginLeft	double	Left PDF "paper" margin in millimeters. Set to zero for border-less and commercial printing applications. Default value is 25.
PaperOrientation	PdfPaperOrientation	The PDF paper orientation, such as Portrait or Landscape. Default value is Portrait.
PaperSize	PdfPaperSize	Sets the paper size
SetCustomPaperSizeinCentimeters	double	Sets the paper size in centimeters.
SetCustomPaperSizeInInches		Sets the paper size in inches.
SetCustomPaperSizeinMilimeters		Sets the paper size in millimeters.
SetCustomPaperSizeinPixelsOrPoints		Sets the paper size in screen pixels or printer points.
PrintHtmlBackgrounds	Boolean	Indicates whether to print background colors and images from HTML. Default value is true.
RequestContext	RequestContexts	Request context for this render, determining isolation of certain resources such as cookies.
Timeout	Integer	Render timeout in seconds. Default value is 60.
Title	String	PDF Document Name and Title metadata, useful for mail-merge and automatic file naming in the IronPdf MVC and Razor extensions.
ForcePaperSize	Boolean	Force page sizes to be exactly what is specified via IronPdf.ChromePdfRenderOptions.PaperSize by resizing the page after generating a PDF from HTML. Helps correct small errors in page size when rendering HTML to PDF.
WaitFor	WaitFor	A wrapper object that holds configuration for wait-for mechanism for users to wait for certain events before rendering. By default, it will wait for nothing.

Ready to see what else you can do? Check out our tutorial page here: Convert PDFs

Frequently Asked Questions

What are rendering options in PDF generation?

Rendering options in PDF generation refer to settings and configurations that determine how a PDF document is created, displayed, and printed. These options include rendering form fields, enabling JavaScript, generating a table of contents, adding headers and footers, adjusting margins, setting paper size, and more, which can be managed using IronPDF.

What is the purpose of a class that provides various rendering options for PDFs?

The ChromePdfRenderer class in IronPDF provides various rendering options that allow users to customize how PDFs are generated. It includes features like PaperFit, which controls content layout on PDF pages, offering different layout styles such as responsive CSS3 layouts or continuous feed.

How can I start using rendering options in PDF generation?

To start using rendering options with IronPDF, download the C# library, prepare the HTML assets or file to convert into PDF, instantiate the ChromePdfRenderer class, access the RenderingOptions property to configure settings, and render the PDF in the desired format.

Can rendering options be used for non-HTML to PDF conversions?

Yes, while many rendering option properties are specifically designed for HTML-to-PDF conversion, they can also be applied to other types of PDF conversions, such as rendering Markdown syntax to PDF using IronPDF.

How do I enable JavaScript when rendering PDFs?

To enable JavaScript when rendering PDFs with IronPDF, set the EnableJavaScript property to true in the RenderingOptions of the ChromePdfRenderer class.

What is the purpose of a manager that controls content layout on PDF pages?

The PaperFit manager in IronPDF controls how content is laid out on PDF 'paper' pages. It offers various layout options such as Default Chrome Behavior, Zoomed, Responsive CSS3 Layouts, Scale-To-Page, and Continuous Feed style setups.

How can I set custom paper sizes in PDF generation?

In IronPDF, you can set custom paper sizes using methods such as SetCustomPaperSizeinCentimeters, SetCustomPaperSizeInInches, SetCustomPaperSizeinMilimeters, or SetCustomPaperSizeinPixelsOrPoints.

What is the default paper orientation in PDF generation libraries?

The default paper orientation in IronPDF is Portrait.

How do I apply custom CSS styles when rendering HTML to PDF?

To apply custom CSS styles when rendering HTML to PDF in IronPDF, use the CustomCssUrl property to specify a local file path or a remote URL for the CSS style-sheet.

Can I create editable PDF forms from HTML form elements?

Yes, you can create editable PDF forms from HTML form elements using IronPDF by setting the CreatePdfFormsFromHtml property to true in the RenderingOptions.

Chaknith related to All Rendering Options

Chaknith Bin

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Software Engineer

Chaknith is the Sherlock Holmes of developers. It first occurred to him he might have a future in software engineering, when he was doing code challenges for fun. His focus is on IronXL and IronBarcode, but he takes pride in helping customers with every product. Chaknith leverages his knowledge from talking directly with customers, to help further improve the products themselves. His anecdotal feedback goes beyond Jira tickets and supports product development, documentation and marketing, to improve customer’s overall experience.When he isn’t in the office, he can be found learning about machine learning, coding and hiking.