.NET eSignature APIs

Automate document signing process - Electronically sign Microsoft Word, Excel, PowerPoint and PDF documents in .NET applications

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.NET e-Signature API

GroupDocs.Signature for .NET


GroupDocs.Signature for .NET allows developers to write applications with the ability to significantly sign electronic docs of various file formats. This e-signing API permits the users to add different types of signatures like text, image or digital signatures on electronic documents. The quite captivating fact about the API is, its UI less and independent calls can be made.

Using .NET digital signature API, users can easily sign their password protected personal or business documents. e-Sinature API permits users to add eSignatures with its own required manageable properties such as dimension, alignment, and protection. Moreover, API can be utilized for Text and Digital signature verifications.

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Advanced .NET Digital Signature API Features



Upload, type or draw signatures


REST API solution so integrated on desktop, mobile and web


Multiple supported document formats


Multiple template elements formatting support


Multiple signature types and properties


Text verification for all document types


Digital signature verifications for all types


Changing output save format support


Change, add or remove passwords


Image manipulating effects on signature


Generate text as image and apply image filters


Setup signature on arbitrary pages like first, last, even, odd etc


Different Image Appearance to apply transparency, borders, etc


Manipulate signature margins


Different measure units support like pixels, percents, millimeters


Search QR-Code and Barcode Signatures for all document types


Sign documents with barcode and QR-Code


Obtain search, verification and signing progress


Metered licensing


Encode and search custom object to QR-Code Signature


Custom serialization & encryption for QR Code signature embedded objects


Measure Types


Ability for cancellation of verification, signature and search process

Multiple Signature Types

  • Text

Add text signature - C#

 // setup Signature configuration
SignatureConfig config = new SignatureConfig();
config.StoragePath = @"D:\storage\"; 
 // Initailize the signature handler
SignatureHandler handler = new SignatureHandler(config);
// setup text signature options
PdfSignTextOptions signOptions = new PdfSignTextOptions("John Smith"); 
signOptions.Left = 100; 
 // Sign document 
string signedPath = handler.Sign<string>("test.pdf", signOptions, new SaveOptions { OutputType = OutputType.String, OutputFileName = "Pdf_Documents_Simple" });
  • Image
  • Digital signatures
  • QR-Code
  • Barcode
  • Stamp

Common Text, Image and Digital Signature Properties

  • Document page number
  • Height
  • Left
  • Sign all pages
  • Top
  • Width
  • TEXT only for Text and Image properties

Specific Digital Signature Properties

  • Digital certificate
  • Document page number
  • Horizontal alignment
  • Image file name
  • Image stream
  • Password
  • Rectangle
  • Signature
  • Vertical alignment
  • Visible

Support and Learning Resources


GroupDocs.Signature offers individual electronically document signing APIs for other popular development environments as listed below: