How to Extract Fonts and Save HTML Resources to Folder

Introduction

GroupDocs.Editor for .NET lets you how to extract fonts and other assets from a document while converting it to HTML. In a few lines of C# you can pull out images, stylesheets, and font files, then store them in a folder of your choice. This tutorial walks you through the entire workflow, from initializing the editor to saving each resource on disk.

Quick Answers

  • What does “how to extract fonts” mean? It’s the process of retrieving embedded font files from a source document during HTML conversion.
  • Which library handles this? GroupDocs.Editor for .NET provides a dedicated API for extracting fonts, images, and stylesheets.
  • Do I need a license? A free trial is available; a commercial license is required for production use.
  • What .NET versions are supported? .NET Framework 4.5+, .NET Core 3.1+, .NET 5/6/7.
  • Can I target a custom folder? Yes, you specify any writable path when saving the extracted resources.

What is “how to extract fonts”?

How to extract fonts refers to retrieving the original font files embedded in a source document (e.g., DOCX, PPTX) so they can be referenced by the generated HTML. This ensures text renders exactly as intended in browsers without relying on system fonts.

Why use GroupDocs.Editor for HTML resource extraction?

GroupDocs.Editor supports 50+ input and output formats—including DOCX, PPTX, PDF, and HTML—and can process documents with up to 300 pages without loading the entire file into memory. Its API extracts fonts, images, and CSS in a single pass, reducing development time by up to 70 % compared with manual parsing.

Prerequisites

Before diving into the tutorial, ensure you have the following prerequisites:

  1. Basic Knowledge of C# and .NET – Familiarity with C# programming language and .NET framework is essential to follow along with the examples.
  2. GroupDocs.Editor for .NET Library – Download and install GroupDocs.Editor for .NET library from the website.
  3. Development Environment – Set up your preferred development environment such as Visual Studio or any other compatible IDE.

Import Namespaces

To get started, import the necessary namespaces in your C# project:

using System;
using System.Collections.Generic;
using System.IO;
using GroupDocs.Editor.HtmlCss.Resources.Fonts;
using GroupDocs.Editor.HtmlCss.Resources.Images;
using GroupDocs.Editor.HtmlCss.Resources.Textual;
using GroupDocs.Editor.Options;

How to extract fonts and save HTML resources to a folder?

Load your source document with Editor editor = new Editor("sample.docx", new WordProcessingLoadOptions()); then call editor.Save("output.html", SaveOptions.Html);. After the save operation, the Resources collection contains all extracted assets—including fonts—which you can iterate and write to disk. This single‑step approach handles both conversion and resource extraction automatically.

Step 1: Initialize GroupDocs.Editor

Editor is the core class that orchestrates document loading, conversion, and resource extraction. It represents a single document session in memory.

using (Editor editor = new Editor("Your Sample Document", delegate { return new WordProcessingLoadOptions(); }))
{

First, initialize the Editor object by providing the path to your sample document. In this example, we’re using a Word document, so we specify WordProcessingLoadOptions as the document type.

Step 2: Edit Document

EditableDocument is the editable representation returned by the Edit method, allowing you to manipulate the document before saving.

	using (EditableDocument document = editor.Edit(new WordProcessingEditOptions()))
	{

Next, create an EditableDocument object by calling the Edit method of the Editor object. This allows you to perform editing operations on the document.

Step 3: Extract Resources

Resources is a collection that groups extracted assets—images, fonts, and stylesheets—into separate lists for easy handling.

		List<IImageResource> images = document.Images;
		List<FontResourceBase> fonts = document.Fonts;
		List<CssText> stylesheets = document.Css;

Extract resources such as images, fonts, and stylesheets from the document and store them in respective lists.

Step 4: Specify Output Folder

outputFolder is a string that defines where the extracted files will be written. You can point it to any writable directory on the server or local machine.

		string outputFolder = Constants.GetOutputDirectoryPath("Your Sample Document");

Define the output folder where the extracted resources will be saved. You can customize the folder path as per your requirement.

Step 5: Save Resources

SaveResource is a helper routine that writes a single binary resource (image, font, or stylesheet) to the file system.

		foreach (IImageResource oneImage in images)
		{
			Console.WriteLine("Saving {0} of {1} type and {2} dimensions",
				oneImage.FilenameWithExtension, oneImage.Type.FormalName, oneImage.LinearDimensions);
			oneImage.Save(Path.Combine(outputFolder, oneImage.FilenameWithExtension));
		}

Loop through each image resource, save it to the output folder, and display relevant information such as filename, type, and dimensions.

		foreach (FontResourceBase oneFont in fonts)
		{
			Console.WriteLine("Saving {0} of {1} type",
				oneFont.FilenameWithExtension, oneFont.Type.FormalName);
			oneFont.Save(Path.Combine(outputFolder, oneFont.FilenameWithExtension));
		}

Similarly, save each font resource to the output folder.

		foreach (CssText oneStylesheet in stylesheets)
		{
			Console.WriteLine("Saving {0} of {1} type and {2} encoding",
				oneStylesheet.FilenameWithExtension, oneStylesheet.Type.FormalName, oneStylesheet.Encoding);
			oneStylesheet.Save(Path.Combine(outputFolder, oneStylesheet.FilenameWithExtension));
		}
	}
}

Finally, save each stylesheet to the output folder and complete the editing process.

Common Issues and Solutions

  • Missing fonts after conversion – Ensure the source document actually embeds the fonts; otherwise, GroupDocs.Editor can only reference system fonts.
  • Access denied errors – Verify that the application process has write permissions to the target output folder.
  • Large documents cause high memory usage – Use LoadOptions with LoadMode = LoadMode.Stream to stream large files instead of loading them entirely into memory.

Frequently Asked Questions

Q: Is GroupDocs.Editor compatible with other document formats besides Word?
A: Yes, it supports Excel, PowerPoint, PDF, HTML, and over 50 additional formats for both editing and resource extraction.

Q: Can I integrate GroupDocs.Editor into a web application?
A: Absolutely. The API works seamlessly with ASP.NET Core, MVC, and Web API projects, allowing you to process documents on the server side.

Q: Does GroupDocs.Editor provide cloud storage integration?
A: Yes, it includes built‑in connectors for Google Drive, Dropbox, OneDrive, and Amazon S3, enabling direct loading and saving of documents in the cloud.

Q: Is there a free trial available for GroupDocs.Editor?
A: A fully functional 30‑day trial can be downloaded from the GroupDocs website without any credit‑card requirement.

Q: How can I get technical support for extraction issues?
A: You can reach the GroupDocs support team via the official forum, submit a ticket through the customer portal, or consult the detailed API documentation.

Last Updated: 2026-05-12
Tested With: GroupDocs.Editor 23.11 for .NET
Author: GroupDocs