GroupDocs.Signature for .NET

Create, apply, and verify digital signatures in documents with an advanced .NET e-signature API. Add electronic, barcode, QR-code, image, text, metadata, and form field signatures to 90+ document formats including PDFs, Word, Excel, Images, and more.

✅ Supports create digital signature, esign pdf, sign pdf doc, verify signature, and remove signatures features across multiple platforms.

🚀 Key Features

• Add electronic signatures to 90+ document formats including PDF, DOCX, XLSX, PPTX, PNG, TIFF, and more
• Create signatures from image, barcode, QR code, stamp, text, metadata, or form fields
• Support for signature validation, verification, and removal
• Search and remove existing signatures from documents
• Apply multiple signatures of different types to a single document
• Built-in support for digital certificates (X.509, PKCS#7) for legally binding signatures
• Metadata signatures for document tracking and authentication
• Form field signatures for interactive document workflows
• Integrate into your signature app or web-based e-sign platform

🔧 Supported Signature Types

Signature Type	Description
Digital Signatures	X.509 certificate-based signatures for legal compliance
Image Signatures	Draw or upload images (PNG, JPEG, SVG, BMP)
Text Signatures	Add custom text annotations with fonts & styles
QR-Code Signatures	Generate QR codes with custom data/format
Barcode Signatures	Add/search/remove barcodes from documents
Stamp Signatures	Custom stamps with date/user info/company logos
Metadata Signatures	Hidden signatures for document tracking & authentication
Form Field Signatures	Interactive signature fields for workflows

📁 Supported Document Formats (90+)

Office Documents:

• Microsoft Word (DOC, DOCX, DOCM, DOT, DOTX, DOTM)
• Excel (XLS, XLSX, XLSM, XLSB, XLT, XLTX, XLTM)
• PowerPoint (PPT, PPTX, PPTM, PPS, PPSX)
• Visio (VSD, VSDX, VSS, VSSX, VST, VSTX)

PDFs & Images:

• PDF (Portable Document Format)
• Images (PNG, JPG, JPEG, BMP, TIFF, GIF, SVG, WEBP)

Other Formats:

• OpenDocument (ODT, ODS, ODP)
• Text files (TXT, RTF, CSV)
• Web formats (HTML, HTM)
• And many more...

💡 Use Cases

• Sign PDF documents with digital certificates (X.509, PKCS#7)
• E-sign Word documents with image signatures or typed names
• Add signatures to Excel spreadsheets and CSV files
• Verify and validate e-signatures for authenticity
• Search and remove existing signatures from documents
• Metadata signatures for document versioning and tracking
• Form field signatures for interactive document workflows
• Batch processing multiple documents with signatures

Example: Sign PDF Document with Image Signature

using GroupDocs.Signature;
using GroupDocs.Signature.Options;

// Initialize signature with input document
using (Signature signature = new Signature("document.pdf"))
{
    // Configure image signature options
    ImageSignOptions options = new ImageSignOptions("signature.png")
    {
        Left = 100,
        Top = 100,
        Width = 200,
        Height = 80
    };
    
    // Sign document and save
    SignResult result = signature.Sign("signed.pdf", options);
    Console.WriteLine($"Document signed with {result.Signatures.Count} signature(s)");
}

☝️ This example shows how to sign a PDF with an image signature using GroupDocs.Signature for .NET.

📦 Installation

Install via NuGet Package Manager:

dotnet add package GroupDocs.Signature --version 25.6.0

Or via Package Manager Console:

Install-Package GroupDocs.Signature -Version 25.6.0

Or download directly from the Releases.

📚 Documentation & Resources

• Official Documentation
• Code Examples
• NuGet Package
• Free Support Forum

🖥️ Cross-Platform Support

GroupDocs.Signature supports:

• .NET Framework (2.0+, including 4.6.2+)
• .NET Core 2.0 and above
• .NET Standard 2.0 / 2.1
• .NET 6.0+
• Mono Framework 1.2+
• Platforms: Windows, Linux, macOS
• Cloud: Azure, AWS, Google Cloud Platform

Why Choose GroupDocs.Signature?

• High-performance signature processing for enterprise applications
• Zero dependencies on external tools like Adobe Acrobat or Microsoft Office
• Memory-efficient processing of large documents
• Thread-safe operations for multi-threaded applications
• Comprehensive API with 90+ supported document formats
• Easy integration into existing .NET signature applications
• Regular updates with new features and format support

Security & Compliance

• Digital Certificate Support: RSA, DSA, ECDSA algorithms
• Standards Compliance: PKCS#7, X.509, PDF/A compatibility
• Signature Validation: Timestamp verification and certificate chain validation
• Legal Compliance: Suitable for legally binding digital signatures worldwide
• Audit Trail: Complete signature history and document integrity verification

Looking for GroupDocs.Signature for Java?

👉 View the Java version here

Contribute

This repository contains examples and demos for GroupDocs.Signature for .NET. We welcome contributions and feedback!

• Report Issues
• Fork the repo and submit pull requests with improvements
• Help improve documentation and examples

📜 License

This project is licensed under the GroupDocs EULA.