Powerful PDF Merger for .NET Environment

From within any .NET application (using C# or VB.NET), Foxit PDF Merger for .NET SDK allows .NET software developers the ability to take any existing PDF document and merge, stamp, append, form fill, flatten, encrypt, rotate, scale, split and so much more. Use an entire PDF document or just specific PDF pages. Add content to existing PDF pages or create new pages from scratch. Do all of this using an object model that is intuitive and easy to learn yet flexible enough to put the power into the hands of the developer.

Flexible Licensing

Foxit PDF Merger for .NET SDK is available in two licensing models. Server-based licensing is intended for developers who wish to install our software on their server or web server. It is licensed per production server and allows an unlimited number of installations on development workstations and development servers. This licensing model is ideal for those who wish to install our software on a limited number of servers and allows us to offer a lower price to developers who do not intend to distribute our software to a large number of servers or workstations.

Developer based licensing is intended for developers who wish to distribute our software to a large number of clients. It allows one developer to develop an unlimited number of client or server-based applications that use our product and distribute them royalty free. Our assemblies can easily be deployed with another application using XCOPY or a setup program.


Performance was a major consideration during the development of Foxit PDF Merger for .NET SDK. The techniques used to parse and manage the imported data are extremely fast and well designed. Only the data required in the output document is parsed and commonly used documents or pages can be stored as static variable to eliminate repeated parsing of the same data. This results in extremely fast performance.

Ease of Use

The Foxit PDF Merger for .NET SDK object model is intuitive and easy to learn.

Two documents can be merged together and output to a Web Form, file, byte array, or System.IO.Stream object with just two lines of code:
MergeDocument document = MergeDocument.Merge( @”C:\DocA.pdf”, @”C:\DocB.pdf” ); 
document.Draw( @”C:\DocOut.pdf” );

Documents can be appended to an instantiated MergeDocument with one line of code:
document.Append( @”C:\DocC.pdf” );

A page (or range of pages) can be appended to an instantiated MergeDocument object with one line of code:
document.Append( @”C:\DocC.pdf”, 2, 1 );


The Foxit PDF Merger for .NET SDK object model is very flexible and can be used to achieve many PDF manipulation tasks. The MergeDocument object can be used to merge and append PDF documents. Pages from the resulting document can then be accessed and new content can be added to the pages.

Foxit PDF Merger for .NET SDK also includes an ImportedPage object that can be used to add content to an imported page using the Generator for .NET object model. This object inherits from the Generator for .NET’s Page object and can have Page Elements or Custom Page Elements added to it. This is ideal for form filling or using an existing PDF document as a template.

The included ImportedPageArea and ImportedPageData objects are Page Elements that allow an imported page to be placed on a Generator for .NET page and be scaled, shifted or rotated. This allows multiple pages from an existing PDF to be placed onto one page. This is ideal for pre-press work as well and using existing PDF documents as templates for portions of a page.

Objects and methods are also included for reading the content from an imported page and for determining the number of pages in an imported PDF document.


We now support iOS 13 Dark Mode and have added a number of UI level improvements, support to play and flatten sound annotations, functionality to manage trusted certificates for signatures and a synchronized update for Xamarin, Cordova, React Native, Kotlin and Flutter!

Foxit PDF SDK 7.1 for Windows, Mac & Linux comes with support for PDF compliance conversion to PDF versions 1.3-1.7, new performance-enhancing APIs for PDF merging, video/audio annotations, improvements to XFA form fields and much more.


Foxit PDF Merger for .NET SDK is a great value. For larger quantities, please contact at or by calling +1-866-680-3668.

Foxit provides email and phone support. Support can be contacted through or by calling +1-866-MYFOXIT or +1-866-693-6948.

*We Offer a 30% discount when you purchase 5 to 9 developer licenses and a 50% discount when you purchase 10 or more developer licenses.