Native .NET API for Electronic Signatures

Add Digital Signatures to Document Formats & Implement popular eSignature Types (Text, Image, QR-Code, Barcode, Stamp, & Metadata) in .NET Applications.

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.NET e-Signature API

GroupDocs.Signature for .NET


Use GroupDocs.Signature for .NET API to build applications in C#, ASP.NET and other .NET-based technologies, that allow you to sign digital business documents such as PDF, Microsoft Word, Excel spreadsheets, PowerPoint presentations, images, OpenDocument and other industry standard file formats without needing to install any additional software. This electronic signature library is simple to work with and .NET Developers can easily add advanced digital signature features in their applications, empowering users to securely sign, search and verify e-Signatures from popular document formats. It supports implementing a variety of signature types like text, image, barcode, QR-code, form field, stamp and metadata.

The document signature API empowers you with simple and advanced search options to locate your required signatures on a document in a flash. The options to apply signature styling, appearance management and customize signature properties such as dimensions, shadow, alignment and more is also doable with this feature-rich document signing API.

GroupDocs.Signature for .NET can be used in any development environment that supports .NET platform. It is compatible with all .NET based languages and supports popular operating systems (Windows, Linux, MacOS) where Mono or .NET frameworks (including .NET Core) can be installed.

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GroupDocs.Signature for .NET Features



Set Height, Width, Margins & Alignment for Text or Image Signature & Place on Specific Page


Supports Rounded Corners for Rectangular Stamp Signature Types


Apply Text or Image Signature on Specific Excel Sheet or Set eSignature across all Sheets


Specify Particular Row & Column Number to Place Text or Image Signature in Excel Sheet


Apply Shadow to Text Signature in Microsoft PowerPoint & Setup its Color, Angle & Transparency


Configure Text Signature Border Styles & Font Options for Excel Sheets


Set Image Signature Type, e.g. Round or Square & Configure Margins, Font Color, Rotation


Apply Digital Certificates to Documents, Spreadsheets & PDF File with Signature Line


Perform Color Settings, Apply Transparency & Rotation to Text Signature


Setup Brightness & Grayscale Options & Specify Indentation of Image Signature in an Image


Embed Custom Objects, Serialize as well as Encrypt and Decrypt Metadata Signature Values of PDF Document


Make eSignature Visible or Hidden in PDF Documents


Sign PDF Documents with Digital Form Field, and Text Signature as Image, Annotation, Sticker or Watermark


Put Text Signature into Form Fields of MS Word & PDF Documents


Specify Arbitrary Pages of Documents for Processing Signature or eSignature Extended Verification for Word Files


Save Signed Image File in Different Format & Export Signed Spreadsheet as Image or Multi-Page TIFF


Assign, Modify & Remove Password to Signed Files & Apply eSignature to Password Protected Files


Electronically Sign Excel Worksheets, PowerPoint Slides, Word Documents & Images with Custom Objects in Metadata


Setup Signature Brush Styles as Solid, Texture, Linear Gradient & Radial Gradient


Add Custom Data Object, VCard or Email Object to QR-Code & Verify Encrypted QR-Code in PDF Files


Sign Documents with Custom Encrypted QR-Code Text or Data


Search & Sign Files with DjVu Format as Image Document


Extract Document Information, e.g., Page Count, through File URL


Search, Sign & Verify CorelDraw Files as Image Documents

Easily Add Digital Signatures

GroupDocs.Signature for .NET API allows you to add various types of signatures to supported file formats. The signature types, such as Text, Image, Digital, Stamp, QR-Code, Barcode, and Metadata can be applied using GroupDocs.Signature for .NET. Following code example shows how to apply text signature to a PDF document:

Apply Text Signature to a PDF Document using C#

using (Signature signature = new Signature("D:\\sample.pdf"))
TextSignOptions options = new TextSignOptions("John Smith")
 // set Text color
ForeColor = Color.Red
// sign document to file
signature.Sign("D:\\signed.pdf", options);

Supported Barcode Signature Types

Our signature manipulation API offers you feature to apply barcode signatures to supported document formats. GroupDocs.Signature for .NET supports various barcode types, such as, Code128, Code39Extended, Code39Standard, EAN14, EAN8, ITF14, UPCA, and UPCE. A static object named “AllTypes” is also provided to support all registered barcode types.

Search Signatures & Certificates

GroupDocs.Signature for .NET API, allows you to search for Digital certificates from Word documents, Excel spreadsheets, and PDF files. You can also fetch all digital certificates registered in system. Metadata signatures can also be searched in Word documents, Excel spreadsheets, images and PDF files, using GroupDocs.Signature for .NET API.

Through GroupDocs.Signature for .NET API, you can search QR-Code and Barcode signatures in any document, presentation, spreadsheet, image, as well as PDF file, and fetch the search progress. You can also search custom data object from documents signed with QR-Code Signature.

Advanced Search Options for Barcode

You can search and locate your required barcode through GroupDocs.Signature for.NET API very easily, as our signature API offers advanced search options. These enable you to search barcode on a particular page, search throughout a document, specify different pages to search (first, last, even, odd), search for barcode of particular encoding type, search barcode based on specific text string, or search barcode based on string with “contains” option.

Support and Learning Resources


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