List of the Top 11 Free PDF SDK in 2025

Pdftools offers robust solutions for handling vast numbers of documents, potentially reaching into the millions. Tailored for sectors that heavily rely on documentation, the Pdftools suite of SDKs aims to enhance the speed, simplicity, and overall ease of your document workflows, reducing stress along the way. Built on reliable SDKs and APIs, Pdftools products integrate effortlessly into your current systems and applications. With the capacity to process thousands of documents each minute, our tools prioritize speed and efficiency. As engineers committed to excellence, we ensure that only the most trustworthy, usable, and well-documented platforms are utilized. While file sizes can be minimized, we guarantee that quality and interactivity remain intact. Additionally, our solutions help ensure that your documents adhere to long-term archiving standards. Comprehensive documentation accompanies every aspect of our products, allowing for a seamless onboarding experience. With Pdftools, you can transform your document management approach and unlock new efficiencies.

Global OEMs, SaaS providers, and enterprise users utilize the Adobe PDF Library to streamline the processes of creating, editing, and managing PDF documents. As an authorized Adobe partner, our SDK is built using the same source code as Acrobat, ensuring top-notch stability, reliability, and quality. Supported programming languages include .NET, .NET Framework, Java, and C/C++, and it is compatible with platforms such as Windows, Linux, and MacOS, with package management facilitated through NuGet and Maven. The library boasts a wide range of capabilities, encompassing annotations, content creation and modification, color management, and various extraction options for text, images, and forms. It also offers features for compression, optimization, and conversion to formats like PDF/A, PDF/X, EPS, PostScript, XPS, and ZUGFeRD, along with robust display and printing options. Moreover, it allows for the import, export, and flattening of both static and dynamic XFA forms, along with AcroForms, and supports a variety of image operations including extraction, rendering, and thumbnail creation. The optimization functionality enhances file size and content, while OCR capabilities enable text addition to documents and images. Additionally, users can convert PDFs to Office formats such as Word, Excel, and PowerPoint, and implement security measures including viewer settings, redactions, password protection, encryption/decryption, and watermarking. Pricing structures are adaptable for OEMs, SaaS solutions, and end-users, based on their specific usage needs. Accelerate your development process and reach the market more swiftly with the Adobe PDF Library; take advantage of the free trial available for download today.

The pdfRest API Toolkit was crafted by developers for developers, enabling swift integration of PDF workflows into business applications with ease and efficiency. This toolkit encompasses a comprehensive suite of PDF processing tools created by digital document specialists who possess decades of expertise to simplify your tasks: it offers conversions such as PDF to Word, PDF to Excel, and PDF to PowerPoint, along with functionalities like adding to PDFs, text extraction, querying PDFs, converting to various formats, and compressing PDFs. Additionally, it provides features for flattening forms, transparencies, annotations, and layers, as well as merging, splitting, encrypting, decrypting, and watermarking PDFs, along with form data management, OCR capabilities, and file uploads and zipping. Users will find extensive documentation featuring intuitive endpoints and parameters, along with sample code in .NET, JavaScript, Python, PHP, and cURL for every endpoint to facilitate smooth operation. Powered by the renowned Adobe® PDF Library™, it allows users to begin without any financial commitment and offers competitive pricing suitable for projects of any scale. The design of pdfRest emphasizes flexibility, allowing APIs to be accessed from any programming language capable of making API requests, making it a versatile choice for developers aiming to simplify their PDF workflow. Start your journey with your first API call today and experience the ease of PDF management firsthand.

KDAN PDF Reader serves as a comprehensive PDF management solution, allowing users to edit, sign, perform OCR scans, convert, annotate, and fill out forms within PDF documents seamlessly. By incorporating advanced AI capabilities, it enhances the efficiency of your document workflows! Tailored for Mac, iPhone, and iPad users, KDAN PDF Reader is a reliable choice for millions, thanks to its extensive features and user-friendly design. KEY FEATURES EDIT TEXT & PDF • Correct mistakes and typos directly in the PDF - replace, insert, or remove text in documents • Modify images by adding, editing, cropping, and adjusting them within PDFs • Include headers and footers for better organization • Utilize Bates numbering for effective referencing, tracking, and systematic arrangement • Apply stamps or dynamic stamps to convey status, offer feedback, and emphasize key information in the document CONVERT PDF • Offline file conversion - change files without needing an internet connection • Transform PDFs into Office file formats, images, or ePub • Supported formats include docx, xlsx, csv, pptx, rtf, txt, html, jpg, png, BMP, jpg200, pub, and MOBI SIGN & FORMS • Fill out and modify forms as needed • Design fillable forms complete with buttons, checkboxes, and list boxes • Create and apply signatures directly on PDFs • Generate signatures using a trackpad, keyboard, or images EDIT PAGE • Combine and separate PDFs effortlessly • Extract, rearrange, rotate, remove, and crop individual PDF pages • Modify the background color of PDFs for enhanced visibility • Add pages from other documents for comprehensive project management. This makes KDAN PDF Reader not just a tool, but a complete solution for all your PDF needs.

ComPDFKit provides a high-quality PDF SDK, API, and Server tailored for businesses, organizations, startups, and developers alike. Its platform allows seamless integration of features such as document annotation, editing, conversion, form filling, and signing into various applications or products, which ultimately helps in reducing both time and costs. The software is versatile and works across multiple operating systems, including Windows, Web, Android, iOS, Mac, and Linux, as well as supporting cross-platform frameworks like React Native, Flutter, and Electron with minimal coding effort. Recent updates from ComPDFKit include the following enhancements: 1. ComPDFKit API Register now to receive 1000 free file processing each month, allowing for comprehensive editing and converting of PDF documents, as well as functionalities such as splitting, merging, inserting, rotating, deleting, and extracting PDF pages, alongside OCR processing. 2. Free Online Tools Utilize ComPDFKit's online tools to effortlessly convert PDF files to and from various formats, including docx, xlsx, pptx, png, jpg, html, txt, csv, and rtf. 3. Web Demo Explore the online demo to view, edit, annotate, compare, sign, encrypt, decrypt, watermark PDFs, and create or fill out PDF forms at no charge. 4. Community License Start-up companies and individual developers can benefit from competitive pricing options through ComPDFKit, helping you to develop customized applications while enjoying exclusive discounts and offers. Additionally, the user-friendly interface and comprehensive support further enhance the experience for developers looking to leverage PDF functionalities in their projects.

AmindPDF boasts a highly intuitive user interface that simplifies PDF management for users. It has the capability to identify and extract text from PDFs, allowing for direct editing of paragraphs or entire blocks of text in a seamless manner, akin to the experience in MS Word. For enhancing PDF security, users can easily apply passwords, define document permissions, insert signatures, and add watermarks. Additionally, the software supports batch processing, enabling users to execute multiple operations, including merging, splitting, compressing, numbering, and converting various PDF files simultaneously. AmindPDF is compatible with multiple platforms such as Windows, iOS, and Android, ensuring that users can access its features on both computers and mobile devices, thus facilitating PDF editing or processing at any time and place. Users can effortlessly modify PDF text by adjusting attributes like font, size, color, style, and alignment. They can also manage images within PDFs by selecting, replacing, rotating, cropping, or deleting them as needed. Furthermore, AmindPDF allows the merging of multiple PDF or image files into a single PDF, employing the filenames of the combined documents to create a structured outline within the final merged file, enhancing organization and accessibility. This versatility makes AmindPDF an invaluable tool for anyone needing comprehensive PDF solutions.

FPDF is a PHP tool designed for generating PDF files directly within PHP applications, serving as an alternative to the PDFlib library. The name FPDF reflects its free nature, allowing users to utilize and modify it without limitations to address diverse needs. This library operates without requiring extra PHP extensions, other than Zlib for compression and GD for GIF capabilities, and it is compatible with PHP versions starting from 5.1, extending through PHP7 and PHP8. There is an abundance of tutorials available, making it easy for users to learn how to use FPDF efficiently. Importantly, FPDF accommodates the creation of documents in various languages beyond Western European scripts, including Central, Cyrillic, Greek, and Baltic languages, provided that the necessary TrueType or Type1 fonts are installed. Furthermore, it supports UTF-8 encoding, enhancing its usability for a broader audience. Although the speed of generating documents may not rival that of PDFlib, it remains quite satisfactory for most applications unless highly specific document accuracy is essential. This adaptability and ease of use contribute to FPDF's popularity among developers seeking a reliable and uncomplicated PDF generation tool, ensuring that it remains a valuable asset in the PHP development toolkit.

pdfToolbox offers comprehensive and adaptable PDF processing solutions that can be easily integrated, enabling both rapid visual assessments and the complete automation of extensive file management. Utilizing robust Adobe technology, pdfToolbox proficiently tackles complex challenges, supports color management, facilitates imposition, and enables conversions to and from various PDF formats. This innovative tool is favored by a wide array of users, ranging from small enterprises to large publishing companies and print service providers, including OEMs that embed it into their product lines. The Desktop version acts as a manual tool for PDF preflight and correction, available either as a plug-in for Adobe Acrobat Pro or as an independent application. Tailored for prepress operators, pdfToolbox features a user-friendly interface for all prepress activities, allowing individuals to perform any required task in just three simple steps. Additionally, users can customize their interface to keep their most commonly utilized functions easily accessible, thereby increasing efficiency and optimizing workflows within the printing sector. This adaptability not only enhances productivity but also ensures that professionals can work with greater speed and accuracy, ultimately improving the quality of the final output.

Anvil is a versatile workflow platform based on embedded logic that enables businesses to efficiently manage a large volume of PDFs, which require completion, generation, maintenance, and signing. This platform allows for a tailored approach to handle diverse PDF-related tasks seamlessly.

PDFlib GmbH is wholly committed to the evolution of PDF technology, with its products being utilized by customers since 1997. The company played a pivotal role as a founding member of the PDF Association in 2006, which was previously known as the PDF/A Competence Center. This organization actively monitors industry changes and market trends, ensuring compliance with ISO standards for PDF. PDFlib GmbH's products are accessible globally, boasting a substantial presence in Europe, North America, and Japan. Recognized for its development components, PDFlib excels in the creation and manipulation of PDF documents. Its main goals include the dynamic production of PDFs on web servers and through various applications on servers, desktops, and mobile devices. By employing PDFlib, users can generate PDF documents dynamically from databases, similar to how dynamic web pages are created. Since its establishment in 1997, PDFlib has showcased its adaptability across a wide array of use cases and development environments. Application developers utilize PDFlib to create PDF outputs that encompass text, images, graphics, and interactive elements, solidifying its status as an indispensable tool in contemporary document generation. Furthermore, PDFlib's comprehensive features make it a preferred choice among developers in search of efficient PDF solutions, reinforcing its reputation in the industry.

Vanilla.PDF is a user-friendly toolkit designed for handling PDFs, offering exceptional capabilities. This framework accommodates all PDF standards, including PAdES electronic signatures and the PKCS#11 interface. With a comprehensive documentation and a variety of fully-functional examples, users can be confident that their results align with top market expectations. If you have any inquiries or require assistance, feel free to reach out to us without hesitation!