PDF SDK Libraries

With just a few lines of code, LEADTOOLS libraries empower developers with a comprehensive PDF API to implement reliable and multi-threaded PDF functionality, without the need for third-party dependencies like Acrobat. Robust PDF controls to read, write, convert, and view PDF files can be combined with state-of-the-art OCR, ICR, OMR, Forms Recognition, Virtual Printing, and scanning APIs within LEADTOOLS to create complete solutions that utilize the PDF format.

Accurate viewing

Robust PDF Viewer Controls

Load and view any PDF file using the Document Viewer API framework. Tested against thousands of PDF documents, LEADTOOLS PDF SDK libraries provides impeccable viewing accuracy and speed that tops many market-leading PDF reading applications. LEADTOOLS accounts for common errors and differences between PDF file versions to give programmers peace of mind, minimize their testing phase, and create the best PDF applications faster.

Accurate viewing

PDF Form Fields

With the LEADTOOLS PDF SDK and minimal code, developers can build interactive and automated solutions that load, fill, update, and save PDF form field data. Developers leveraging the Document Viewer can provide users an interface to load and enter data into PDF form fields and then save the PDF. Alternatively, developers can create automated workflows with no user interface that fill in PDF form fields. Further, developers can use LEADTOOLS to parse AcroForms fields and data for additional processing or alternate storage.

LEADTOOLS PDF SDK supports the following field types:

  • Text Box
  • Check Box
  • Radio Button
  • List Box
  • Combo Box (also referred to as Drop-down List or Select List)
Versatile and robust PDF Libraries

Complete PDF Conversion API

The LEADTOOLS Document Converter API can perform any type of conversion to and from PDF. For example, convert to and from PDF: PDF/A, other document and Office formats, images, HTML, EMF, and SVG. There are more than 165 file types are supported. The Document Converter API is flexible and gives you complete control of the conversion.

In addition to changing formats, the LEADTOOLS PDF Conversion API can convert between PDF and PDF/A, convert between PDF standards versions, linearize PDFs for "Fast Web View", and distill Postscript with optimizations for eBook, screen, and pre-press applications.

Secure PDF libraries

PDF Security, Strong Encryption, and Redaction

With standards like HIPAA and GDPR, privacy and the protection of information is a big deal. The LEADTOOLS PDF libraries fully support PDF encryption and PDF Permissions to control editing, printing high and low resolution, and copying content. Additionally, by leveraging PDF image and text redaction and the LEADTOOLS Document Analyzer SDK component, user-defined information such as account numbers and social security numbers can be removed from the PDF automatically.

PDF libraries that support searching and analyzing

Document Search and Analysis

The LEADTOOLS PDF libraries provide APIs to find and manipulate PDF content by using string search or RegEx. For even more power, the AI-enhanced LEADTOOLS Document Analyzer component can find fuzzy matches for such things as account numbers, company names, social security numbers, and more.

PDF libraries that support PDF comparison

Compare PDF Files

The LEADTOOLS Document Compare library is an OEM-ready, zero-footprint document-comparison solution for HTML5/JavaScript front ends with a Microsoft .NET (IIS & Kestrel), or Java (Linux/Apache) hosted back end. Developers can add full-featured PDF comparison technology to their application so that end-users can find and see all text insertions, deletions, and edits in two image or text-searchable PDF files.

Safe digital signatures

Secure Digital Signatures

Digital signatures in PDF files are comparable to ink signatures on a paper document, but much more secure. LEADTOOLS PDF SDK libraries can add digital signatures to PDF files, retrieve information from embedded signatures, as well as verify signatures to ensure that a bad actor has not manipulated the PDF. When combined with the eSignature support integrated in the LEADTOOLS Document Viewer, developers also have the ability to add simple electronic signatures to the PDF before creating the digital verification certificate.

PDF libraries that support annotation

Annotate and Mark Up PDF Files

LEADTOOLS supports reading, displaying, editing, and writing PDF annotations and markups that work seamlessly with Adobe Acrobat and other compliant PDF readers. By annotating and marking up PDF files, users can collaborate by writing comments and drawing shapes on top of the document without making permanent changes. Additionally, sensitive information can be permanently or temporarily redacted to help your application comply with standards such as GDPR and HIPAA.

PDF compression powered by AI

AI-Powered PDF Compression and Optimization

LEADTOOLS uses artificial intelligence to compress and optimize both image and text-searchable PDF file types. LEADTOOLS maximizes image-based PDF compression while maintaining quality with LEADTOOLS advanced MRC image segmentation and compression technologies. LEADTOOLS PDF libraries can also optimize text-searchable PDF files by analyzing document features to find ways to make the resulting file smaller and more efficient.

Process multipage files

Comprehensive Multipage Processing APIs

Comprehensive multipage features include

  • Merge multiple PDF files into a single file
  • Split single multipage files into multiple files
  • Extract, delete, and insert pages
  • Manipulate the order of pages
  • Generation of image thumbnails of any page
Parse and extract PDFs

PDF Parse and Extraction Libraries

With LEADTOOLS, you can parse, update, and extract data such as unicode text and form fields, images, fonts, annotations, shapes, hyperlinks, bookmarks, table of contents, and document metadata. Further, you can update the file settings to set the initial view, create an auto-print PDF, and more.

Portfolio and and attachment PDF libraries

PDF Portfolio and Attachments APIs

LEADTOOLS SDK libraries can process PDF Portfolio and PDF Attachments, alike. The APIs can extract Portfolio metadata as well as extract all embedded files.


  • Loading PDF Portfolio documents
  • Extracting PDF portfolio schema
  • Extracting PDF file within PDF Portfolio documents
  • Loading PDF documents with embedded attachments
  • Extracting PDF attachments embedded within PDF documents
Bookmark support

Thorough PDF Bookmark Functionality

The LEADTOOLS PDF SDK libraries provides functions to extract, update, delete and create PDF bookmarks. Bookmarks greatly improve a user's experience as a navigation mechanism to get readers to a specific part of the document quickly.

Versatile and robust PDF Libraries

Proven PDF Forms API

LEADTOOLS PDF APIs provide everything needed to create applications that use existing PDF, FDF, and XFA Forms, such as getting PDF form field information, programatically fill out forms, extract data from forms.

Versatile and robust PDF Libraries

PDF JavaScript

LEADTOOLS PDF APIs provide the ability to extract, write, replace, and delete existing JavaScript inside PDF documents.

PDF Development Made Easy

Easy to Integrate

LEADTOOLS handles the heavy lifting, eliminating months of R&D, while giving you the best quality and performance available. You'll be free to focus on other components of your application. Download the LEADTOOLS evaluation to streamline your development.

Cross platform libraries

PDF SDK Platforms and Programming Interfaces

Operating Systems

Projects that use LEADTOOLS PDF libraries can be deployed to Windows, Linux, macOS, Android, iOS, and Web devices.


Developers that are leveraging these frameworks can utilize the PDF SDK: .NET 6+, .NET Framework, .NET MAUI, Xamarin, UWP, WinForms, C++ Class Library, ASP.NET, and Web Services / Web API (JSON, SOAP, REST)

Programming, Scripting, Markup

PDF code snippets and demo applications are provided for the following: C#, VB, XAML, C/C++, Java, Objective-C, Swift, and HTML / JavaScript

Start Coding with LEADTOOLS PDF

PDF libraries as well as all LEADTOOLS Recognition, Document, Medical, Vector, and Imaging technologies for all development and target platforms, including Windows, Linux, and macOS.

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Online Demo Applications that include PDF SDK Libraries

HTML5/JavaScript Document Viewer

The Document Viewer for HTML5 and JavaScript is a zero-footprint component to view raster, text, and document formats. It is ideal for Enterprise Content Management (ECM), document retrieval, and document normalization solutions. The following features are demonstrated:

  • Load a document from local disk and url
  • Draw annotations on the document
  • Use thumbnail viewer for page selection
  • View any bookmarks included in the document
  • Interactive zooming/panning
  • Print documents and annotations


LEAD has packaged the LEADTOOLS Document Viewer web application and service into the LEADVIEW API component. It requires as little as three lines of code to plug the LEADVIEW API into any JavaScript application. The component is highly customizable and supports all the features of the existing low-level Document Viewer, including viewing and converting hundreds of file formats and more than 30 annotation and markup objects. Users can easily create themes for the UI or use the predefined dark or light themes. With a settings dialog or JSON file, the entire ReactJS UI can be customized by each end-user or administratively locked down at a server level.

HTML5/JavaScript Document eSignature

Demonstrates how to use LEADTOOLS eSignature support within the Document Viewer to create electronic signatures and digitally sign documents. Comparable to handwritten signatures on a paper document, electronic signatures are much more secure. Add simple electronic signatures to documents or combine the eSignatures with LEADTOOLS certificate-based digital signing for advanced electronic signatures that guarantee the document has not been manipulated.

  • Create eSignatures
  • Add signature fields to your document for any number of signatories
    • Full Name
    • Initials
  • Incorporate certificate-based Digital Signing

To run the demo in Design Mode and add your own signatories and eSignature fields:
To run the demo with sample signatories and eSignature fields already incorporated: