Where does SourceFont live in the IronPDF API?

SourceFont is an abstract class in the PdfToSvg namespace, shipped in IronPdf.dll. It derives from System.Object. Instances are produced internally by the IronPDF PDF-to-SVG conversion pipeline; you receive them through conversion callbacks rather than constructing them directly.

How do you export a PDF font to a WOFF file in C#?

Receive a SourceFont from the SVG conversion API, check that CanBeExtracted is true, then call ToWoff() to get a byte array. Write that array to a file with File.WriteAllBytes, or encode it to Base64 for embedding in a CSS @font-face data URI.

What is the difference between ToOpenType and ToWoff on SourceFont?

Both methods return the same underlying font data as a byte array. ToOpenType packages it as an OpenType (.otf) binary suitable for desktop use or further processing, while ToWoff packages it as a WOFF file optimized for web delivery in a CSS @font-face rule.

How do you tell whether a SourceFont needs to be embedded in an SVG?

Check IsStandardFont first. The 14 PDF standard fonts do not carry embedded data and are expected to be available in every PDF viewer, so embedding them is usually unnecessary. For all other fonts, check CanBeExtracted to confirm the data is available before calling ToOpenType or ToWoff.

Class SourceFont

Inheritance

System.Object

SourceFont

Namespace: PdfToSvg

Assembly: IronPdf.dll

Syntax

public abstract class SourceFont : Object

A font resource extracted from a PDF during SVG conversion is represented as a SourceFont object. When IronPDF renders a PDF page to SVG, every typeface encountered in that page is surfaced through a SourceFont so that downstream code can decide how to handle it: embed the raw bytes, inline the data as a web font, or skip fonts that belong to the PDF standard set.

SourceFont is an abstract base class in the PdfToSvg namespace. Concrete subtypes are produced internally by the conversion pipeline; you do not construct them directly (the constructor is protected). Instead, you receive instances through the SVG conversion API and interrogate them through the properties and methods declared here.

Three boolean properties describe what a given font supports. CanBeExtracted reports whether the underlying font data can be retrieved at all; some fonts in a PDF are partially embedded or restricted, making extraction impossible. CanBeInlined indicates whether the font can be encoded directly into the SVG output as a data URI, which is useful for fully self-contained SVG files. IsStandardFont identifies the 14 PDF standard fonts (Times, Helvetica, Courier, and their variants) that do not carry embedded data because PDF viewers are expected to supply them natively.

The Name property returns the PostScript name of the font as it appears in the PDF. Two conversion methods cover the most common web-font formats: ToOpenType() returns the font bytes as an OpenType (.otf) binary, and ToWoff() returns the same data repackaged as a WOFF file ready for a CSS @font-face rule. Both methods return a byte[], so you can write the result to disk, embed it in a stream, or encode it to Base64 for inlining.

A typical workflow checks CanBeExtracted before calling either conversion method, then branches on IsStandardFont to decide whether embedding is necessary at all.

using PdfToSvg;
using System.IO;

// svgConversion supplies SourceFont instances during PDF-to-SVG rendering
void HandleFont(SourceFont font, string outputDir)
{
    if (font.IsStandardFont || !font.CanBeExtracted)
        return;

    string path = Path.Combine(outputDir, font.Name + ".woff");
    File.WriteAllBytes(path, font.ToWoff());
}

For background on PDF-to-SVG conversion in IronPDF, see the PDF to SVG how-to, the IronPDF get-started guide, and the font handling examples.

Constructors

SourceFont()

Declaration

protected SourceFont()

Properties

CanBeExtracted

Declaration

public virtual bool CanBeExtracted { get; }

Property Value

Type	Description
System.Boolean

CanBeInlined

Declaration

public virtual bool CanBeInlined { get; }

Property Value

Type	Description
System.Boolean

IsStandardFont

Declaration

public virtual bool IsStandardFont { get; }

Property Value

Type	Description
System.Boolean

Name

Declaration

public abstract string Name { get; }

Property Value

Type	Description
System.String

Methods

ToOpenType()

Declaration

public abstract byte[] ToOpenType()

Returns

Type	Description
System.Byte[]

ToWoff()

Declaration

public abstract byte[] ToWoff()

Returns

Type	Description
System.Byte[]