GroupDocs.Viewer for .NET is a versatile API designed for developers to render and convert over 100+ file formats into HTML, PDF, or images with unmatched accuracy. It supports advanced features like document streaming, email attachment handling, custom headers, responsive layouts, and CAD rendering without requiring external software like Microsoft Office. Whether you are working with Word, Excel, Visio, or archive files, GroupDocs.Viewer for .NET ensures seamless integration into .NET web and desktop applications, optimizing file rendering for enhanced user experiences.

GroupDocs.Viewer for .NET Features

Render Word Documents

Render Word Documents as HTML, PDF, and Images

Convert Word documents to HTML, PDF, PNG, or JPEG without using Microsoft Word, suitable for .NET web or desktop apps.

Render PDF Documents

Render PDF Documents as Images

Convert PDF documents to image formats such as PNG or JPEG, ensuring quality control for .NET applications.

Render Spreadsheet Files

Render Excel and Apple Numbers Spreadsheets

Render Excel and Apple Numbers spreadsheets to HTML, PDF, PNG, or JPEG, providing flexibility in .NET applications.

Split a Worksheet into Pages

Split Excel worksheets into pages using custom row or column settings, making large sheets easier to manage in rendering.

Render PowerPoint Presentations

Render PowerPoint Presentations to PDF and Images

Convert PowerPoint slides to PDF, PNG, or JPEG for easy sharing and viewing in .NET projects.

Render Visio Documents

Render Visio Diagrams to PDF and Images

Convert Visio diagrams to PDF, PNG, or JPEG for integration into .NET solutions.

Render CAD Files

Render CAD Drawings and Models

Convert CAD drawings to PDF or image formats for viewing within .NET apps without specialized CAD software.

Specify Rendering Options

Customize CAD Rendering

Use the CadOptions class to specify different settings such as background color and output image size for rendering CAD files to formats like PDF, PNG, and JPEG.

Render Project Files

Render Project Files to Multiple Formats

Render Microsoft Project (.MPP) and other project management files to HTML, PDF, PNG, and JPEG without needing project management software.

Adjust Project Rendering Options

Control output page size, adjust time units, and render specific project details like task notes and specific dates for comprehensive project representation.

Render EBooks

Convert EBooks to HTML, PDF, and Images

Render EPUB, MOBI, and AZW3 eBooks to HTML, PDF, PNG, or JPEG without needing a dedicated book reader.

Render Web Documents

Render Web Documents as PDF or Images

Render HTML, MHTML, and CHM files into PDF, PNG, or JPEG formats with customizable rendering settings, such as page size and margins.

Render XML Documents

Advanced XML Rendering

Process XML documents using an advanced module to ensure correct formatting, highlighting, and pagination, even for heavily corrupted XML structures.

Render Text Documents

Convert Text Documents to Multiple Formats

Render text documents, including XML, to formats like HTML, PDF, and image files, with enhanced options for styling and structuring.

Render Images

Image Conversion to PDF, HTML, or PNG

Render raster images such as JPEG, PNG, and BMP into PDF, HTML, and other formats, with options to adjust output dimensions and quality.

Render Email Messages

Render Email Messages

Render emails in formats like EML, MSG, and MHT to HTML, PDF, or images, supporting different rendering scenarios including attachments.

Render Outlook Data Files

Convert PST and OST Files

Render Outlook PST and OST data files to view their contents, including emails and attachments, in HTML, PDF, or image formats.

Render Lotus Notes Database Files

Render NSF Files

Convert Lotus Notes NSF files to HTML, PDF, or image formats for easy viewing of emails, attachments, and other elements within the database.

Render Archive Files

Render Archive as HTML

Convert archive files such as .ZIP, .RAR, and .7Z to HTML for easy viewing in web browsers.

Render Archive as PDF

Render archive contents into a consolidated PDF file for documentation or sharing purposes.

Render Archive as Images (PNG, JPEG)

Convert archive files into individual images in formats like PNG or JPEG for visual previews.

Load Documents

Load Documents from Local Path

Load a document from a local file system path using GroupDocs.Viewer for rendering.

Load from Stream

Load documents from a memory stream for flexibility in handling file input sources.

Load from URL

Load documents directly from URLs, enabling remote document rendering.

Load from FTP

Load documents stored on an FTP server for easy access and viewing.

Load from Amazon S3 Storage

Load documents directly from Amazon S3 buckets using AWS credentials.

Load from Azure Blob Storage

Load documents from Azure Blob Storage, integrating cloud document access.

Load Password-Protected Documents

Load documents that are protected by passwords, ensuring secure handling of sensitive files.

Document Loading Features

Specify File Type When Loading a Document

Use LoadOptions to specify the file type directly, bypassing automatic detection for better performance.

Specify Encoding When Loading Documents

Control character encoding when loading documents using LoadOptions to ensure accurate content display.

Loading of External Resources Contained by a Document

Manage the loading of external resources such as images by configuring LoadOptions to either skip or whitelist resources for secure processing.

Retrieve Document Information

Retrieve properties such as format family and page count after loading a document to facilitate document rendering or analysis.

Determine File Type

Determine a file type based on extension, media type, or file signature using FileType methods like FromExtension(), FromMediaType(), or FromStream().

Get the Format Family and Additional Information

Get detailed information about the format family to categorize different document formats, such as archives or email files.

Check if a File is Encrypted

Verify whether a file is encrypted by using GetFileInfo() after loading the document, enabling you to handle security features effectively.

Render Documents

List and Print All Supported File Types

Use FileType.GetSupportedFileTypes() to list all supported file types for rendering in your .NET application.

Get the Width and Height of Document Pages

Use viewer.GetViewInfo() to obtain the width and height of each page in a document.

Render Specific Pages

Render only selected pages by specifying them in the View() method either as parameters or by using an array.

Cancel Rendering

Cancel ongoing rendering operations if required to halt the process in real-time.

Render Hidden Pages

Use advanced rendering settings to include hidden pages in the output when necessary.

Rotate Pages

Rotate pages in your document by utilizing the RotatePage method from the ViewOptions class.

Set Custom Fonts

Specify custom fonts to be used when rendering documents to maintain consistency in the output.

Replace Missing Fonts

Replace missing fonts in documents with specific fonts to ensure proper formatting when rendered.

Save Output and Watermark Features

Save Output to Stream

GroupDocs.Viewer allows saving output results to a stream, offering flexibility when rendering to different formats like PDF, HTML, or images.

Add Text Watermarks

Add watermarks to HTML, JPG, PNG, or PDF outputs with simple methods to protect and personalize rendered documents.

HTML Rendering Features

Render to HTML

Convert documents to HTML while embedding or storing resources externally, providing control over document output for web viewing.

Render with Responsive Layout

Enable responsive layout when rendering documents to HTML for consistent viewing across various device types.

Optimize Output for Printing

Use the ForPrinting property to render HTML optimized for print, supporting vector formats like SVG for enhanced quality.

Minify HTML

Minify generated HTML files to reduce size and improve loading speed, particularly useful for web-based viewers.

Exclude Fonts

Exclude unnecessary fonts from the output to minimize the size of the rendered HTML files.

Image Rendering Features

Render to PNG or JPEG

Convert documents to high-quality PNG or JPEG images, specifying output quality and resolution to meet your needs.

Adjust Image Size

Control the size of output images when rendering to PNG or JPEG to optimize for bandwidth and quality requirements.

Rendering Options for PDF and Images

Adjust JPEG Image Quality

Decrease JPEG quality to reduce file size by setting JpgQuality in PdfViewOptions (value between 1-100, default is 90).

Get Text Coordinates

Extract text coordinates in rendered images using ViewInfoOptions.ForPngView() and analyze the text, words, and character locations.

Set Image Size Limits

Set maximum width and height for output images using ImageMaxWidth and ImageMaxHeight properties in HtmlViewOptions or JpgViewOptions.

Render to PDF with Custom Quality

Set image quality in rendered PDFs using PdfOptimizationOptions.ImageQuality to adjust JPEG image quality within the output PDF.

Reorder Pages in PDF

Specify the order of rendered pages by setting the page numbers in PdfViewOptions using the Viewer.View() method.

Protect PDF Document

Add password protection to the output PDF by using the Security option during rendering.

Optimize PDF Output

Minimize output file size by removing unused resources and subsetting fonts during rendering.

PDF File Optimization Features

Optimize PDF File Resources

Reduce the output PDF file size by optimizing images, fonts, form fields, and other document components for efficient storage and faster loading.

Optimize Spreadsheets in PDF Files

Optimize embedded spreadsheets to reduce the overall PDF file size by removing unnecessary borders and specific fonts.

Optimize Images

Reduce image quality, set specific image resolutions, or convert images to grayscale to minimize the PDF file size.

Reduce Image Quality

Enable image compression and adjust the image quality percentage to lower the file size while maintaining acceptable visual quality.

Set Image Resolution

Set a maximum image resolution for the output PDF to optimize file size and enhance loading efficiency.

Convert to Grayscale

Convert images within the PDF to grayscale to further reduce the file size and simplify document content.

Optimize Fonts

Subset fonts used in the PDF file to remove unnecessary characters, reducing the file size without impacting the document’s appearance.

Remove Annotations

Remove any annotations present in the PDF to optimize file size and enhance readability.

Remove Form Fields

Remove fillable form fields in the output PDF to minimize its size while retaining static content.

Optimize PDF File for Browser

Optimize the output PDF file for faster rendering in web browsers, allowing partial download for quick viewing of the first pages.

PDF File Optimization Features

Subset Fonts in PDF

Reduce file size by removing unused instructions from embedded fonts in a PDF by setting the SubsetFonts property to true.

Remove Unused Resources in PDF

Optimize PDF files by removing unused resources, such as orphaned objects or unnecessary data streams, to reduce the document size effectively.

Process Attachments

List Attachments

List attachments from emails, PDFs, Outlook, Lotus Notes, and compressed files with GroupDocs.Viewer using the GetAttachments method.

Save Attachments

Save attachments from supported documents, such as emails and compressed files, by iterating through the attachment collection and using the SaveAttachment method.

Render Attachments

Render document attachments just like any other document by saving and viewing the attachments with the specified view options.

Caching Features

Custom Cache Implementation

Implement a custom caching solution for GroupDocs.Viewer to store document cache in third-party storage like FTP, Amazon S3, Google Drive, or Redis.

Thread-Safe Cache for GroupDocs.Viewer

Create a thread-safe cache for GroupDocs.Viewer to ensure consistent and reliable caching during concurrent access.

Logging

Logging Support

Implement logging in GroupDocs.Viewer to keep track of document rendering and processing operations, ensuring smooth troubleshooting and debugging.

Supported File Formats

Archive and Compression File Formats

CAD and 3D File Formats

Database File Formats

eBook File Formats

Email File Formats

Image File Formats

Note
AI, PSB, and PSD formats, marked by asterisk (*), currently are not supported by the GroupDocs.Viewer.CrossPlatform.

Note-Taking File Formats

Note
Note file formats family currently is not supported by the GroupDocs.Viewer.CrossPlatform.

Outlook Data File Formats

PDF and Page Layout File Formats

Presentation File Formats

Project Management File Formats

Note
Project Management file formats family currently is not supported by the GroupDocs.Viewer.CrossPlatform.

Spreadsheet File Formats

Text and Programming File Formats

Visio File Formats

Note
Visio file formats family currently is not supported by the GroupDocs.Viewer.CrossPlatform.

Web File Formats

Word Processing File Formats

System Requirements

Note:
GroupDocs.Viewer for .NET (including GroupDocs.Viewer.CrossPlatform) does not require external software like Microsoft Word, Excel, or PowerPoint.

Supported Operating Systems

GroupDocs.Viewer for .NET

• Windows
  • Windows Server 2003+
  • Windows XP, Vista, 7, 8, 8.1, 10, 11 (x64, x86)
• Linux
  • Supported distributions include Ubuntu, OpenSUSE, CentOS, and others.
• Mac
  • Supports macOS.

GroupDocs.Viewer.CrossPlatform

• Windows
  • Windows 7.1 SP1, 8.1, 10 (v1607+), 11 (v22000+), Server 2012+, Server Core 2012+, Nano Server (v1809+).
• Linux
  • Supports distributions like Ubuntu, OpenSUSE, CentOS, and others.
• Mac
  • Requires macOS 10.15+.

Supported Frameworks and Runtimes

• GroupDocs.Viewer for .NET

  • .NET Framework 4.6.2+
  • .NET 6+
  • Older versions supported .NET Framework 2.0, 3.5 (dropped in v22.3) and .NET Framework 4.0-4.6.0 (dropped in v23.8).

• GroupDocs.Viewer.CrossPlatform

  • Requires .NET 6.0+ (does not support .NET Framework).

Development Environments

• Microsoft Visual Studio 2010+
• Microsoft Visual Studio for Mac
• JetBrains Rider

Install GroupDocs.Viewer for .NET

Add GroupDocs.Viewer to your .NET project using NuGet or by downloading the required DLLs.

Choose the correct package.

GroupDocs.Viewer

• Target Frameworks: .NET Framework 4.6.2+, .NET 6.0.
• Dependencies: System.Drawing(.Common).

GroupDocs.Viewer.CrossPlatform

• Target Frameworks: .NET 6.0+.
• Preferred for: Linux and macOS.

Install Using NuGet

You can install the library using:

1. NuGet Package Manager
   Open Manage NuGet Packages in Visual Studio, search for GroupDocs.Viewer or GroupDocs.Viewer.CrossPlatform, select the latest version, and click Install.
2. Package Manager Console
   Run the following commands in Visual Studio:

   Install-Package GroupDocs.Viewer
   Install-Package GroupDocs.Viewer.CrossPlatform
   

3. .NET CLI
   Run the following commands in your terminal:

   dotnet add package GroupDocs.Viewer
   dotnet add package GroupDocs.Viewer.CrossPlatform
   

Download from the Website

1. Visit GroupDocs Viewer Releases.
2. Download the ZIP archive or MSI installer.
3. Add the GroupDocs.Viewer.dll to your project:
   • Extract the archive or install the package.
   • In Visual Studio, right-click References/Dependencies → Add Reference.
   • Locate and select GroupDocs.Viewer.dll.

Render Email Messages as HTML with Embedded Resources

Convert email messages into a fully functional HTML file with all external resources embedded, ensuring a seamless viewing experience within your .NET application.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;

// Initialize Viewer for the email file
using (var viewer = new Viewer("sample.eml"))
{
    // Configure to create an HTML file with embedded resources
    var viewOptions = HtmlViewOptions.ForEmbeddedResources("output.html");
    viewer.View(viewOptions);
}

// Result: Generates an HTML file containing the email's content with all resources included.

Convert Documents to Optimized PDF

Transform your documents into optimized, browser-ready PDF files while preserving quality and minimizing file size.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;

// Initialize Viewer for the document
using (var viewer = new Viewer("sample.docx"))
{
    // Configure output to be a PDF
    var viewOptions = new PdfViewOptions("output.pdf");
    // Enable optimization for browsers
    viewOptions.OptimizeForBrowser();
    viewer.View(viewOptions);
}

// Result: Generates a PDF file optimized for web browsers.

Customize Email Header Field Names

Modify the labels of standard email header fields such as “From,” “To,” and “Subject” for personalized rendering in HTML format.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;

// Initialize Viewer for the email file
using (var viewer = new Viewer("sample.eml"))
{
    // Configure output as an HTML file with custom header labels
    var viewOptions = HtmlViewOptions.ForEmbeddedResources("output_custom.html");
    viewOptions.EmailOptions.FieldTextMap[Field.From] = "Sender";
    viewOptions.EmailOptions.FieldTextMap[Field.To] = "Recipient";
    viewOptions.EmailOptions.FieldTextMap[Field.Subject] = "Email Subject";
    viewer.View(viewOptions);
}

// Result: Creates an HTML file with customized email header labels.