List of the Top 25 Free PDF Annotators in 2025

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.

MobiPDF, previously known as PDF Extra, serves as a user-friendly platform for reading and editing PDFs, offering features such as creating, organizing, annotating, filling, signing, converting, and sharing any PDF file. This versatile tool stands out as a cost-effective substitute for Adobe Acrobat Pro, catering to a wide array of user needs. HERE’S WHAT YOU CAN EXPECT WITH MOBIPDF: Multiple Viewing Options: Utilize a focused "Read Mode" for an uninterrupted reading experience. Sophisticated Editing Capabilities: Engage with a PDF editing interface reminiscent of Word. Bidirectional Conversions: Effortlessly transform PDFs into and from formats like Word, Excel, PowerPoint, or images. OCR Integration: Enhance scanned documents by making them searchable. Annotation Features: Utilize tools to highlight, comment, strikethrough, stamp, and more to improve your documents. Simple PDF Management: Easily reorder, compress, split, and merge PDFs as you need. Signing and Security: Incorporate signatures, create and fill out forms, and safeguard your PDFs with passwords, encryption, and digital certificates. Offline Functionality: Continue working on your files without needing an internet connection. Instant Translation: Translate any PDF into over 50 languages with just a click. Overall, MobiPDF combines essential features and user-friendly design, making it a reliable choice for anyone needing comprehensive PDF tools.

SwifDoo PDF is a versatile tool for Windows that serves as a comprehensive PDF maker, reader, editor, and converter. It allows users to effortlessly create, convert, merge, compress, and sign PDF files while offering an intuitive interface that supports the insertion of links or images into documents. Users can convert PDFs into formats such as Microsoft Word, Excel, PowerPoint, JPG, PNG, TIFF, BMP, and even convert CAD files to PDF. The integrated compression feature ensures that files are reduced in size without compromising quality. Additionally, SwifDoo PDF boasts an array of specialized tools for scanning and converting documents, enhancing its functionality. Among its capabilities are PDF reading, annotation (including stamp features), image extraction, editing, compression, merging, splitting, and adding signatures to documents. This all-in-one solution is compatible with various Windows operating systems, including Windows 10, 7, 8, Vista, and XP. The current version available is SwifDoo PDF 2.0.1.9, making it a reliable choice for managing PDF files efficiently.

Enhance your productivity with user-friendly PDF tools designed to streamline your workflow with PDF documents. These tools are completely free and straightforward to utilize! You can easily incorporate text, images, and freehand drawings into your PDFs, fill out forms, and even create a personalized signature for signing documents. Moreover, share your PDF files with confidence through a secure link that expires automatically, ensuring complete privacy with zero-knowledge end-to-end encryption using 256-bit AES technology. This way, your sensitive information remains protected while you collaborate!

PDF Studio Viewer is a reliable and user-friendly document reader that works across multiple platforms. It allows users to annotate and complete interactive forms seamlessly. For those seeking more advanced features, PDF Studio Standard and PDF Studio Pro offer enhanced capabilities. Key features of PDF Studio Viewer include: - High-fidelity PDF display - Annotation and markup tools for PDFs - Functionality to fill and save forms - Support for rendering digital signatures and layers - An intuitive user interface - Enhanced printing and searching options - Options for document storage integration - Integration with DocuSign© With such a comprehensive set of tools, PDF Studio Viewer is an excellent choice for both casual users and professionals alike.

Take advantage of our complimentary Adobe Acrobat Reader to effortlessly view, sign, collaborate on, and annotate your PDF files. With this tool, you can not only view and sign documents but also collect feedback and share PDFs for free. If you wish to enhance your experience, you can subscribe to Acrobat Pro, which provides additional features such as editing, exporting, and sending PDFs for signature requests. Move beyond simply opening and viewing your PDF files; it's easy to annotate your documents and gather input from multiple reviewers into a single shared online PDF. The Acrobat Reader mobile app allows you to conveniently work on your documents from anywhere, equipped with essential tools for converting, editing, and signing PDFs. Moreover, the app lets you use your device's camera to scan documents, whiteboards, or receipts and turn them into PDFs. By connecting to Adobe Document Cloud, Acrobat Reader guarantees that your work with PDFs is accessible no matter where you are, and you can easily manage your files on platforms such as Box, Dropbox, Google Drive, or Microsoft OneDrive. This smooth integration offers a flexible and efficient workflow, enhancing your document management experience like never before, ensuring your productivity remains uninterrupted. Thus, whether you're working on a personal project or collaborating with a team, Adobe Acrobat Reader provides a comprehensive solution for all your PDF needs.

Drawboard PDF - Robust PDF capabilities. Experience the most user-friendly PDF editing and annotation application available for Windows, iOS, macOS, Android, and the web. Drawboard PDF – Essential features available for free! Effortlessly mark up and edit any PDF as if you were using pen and paper. PDF ANNOTATION TOOLS THAT ENABLE YOU TO ACHIEVE GREAT THINGS. DRAW Access a full suite of inking tools designed for marking up documents and collaborating with a natural feel reminiscent of writing with a pen. INSERT Add whatever you require; including text, notes, callouts, signatures, images, audio notes, and much more. MEASURE Utilize measurement tools tailored for technical professionals in fields like Architecture, Construction, and Manufacturing. Obtain precise measurements of elements on the page with straightforward calibration. ORGANIZE Keep all your documents conveniently stored in one location, whether on your device or in the cloud. Effortlessly merge, split, compress, and rearrange PDFs as you wish. CROSS-PLATFORM Seamlessly work from any location on any device, collaborating in real-time! COLLABORATE Engage in instant collaboration directly on the document. Conduct your work where it’s actually needed. Invite team members to collaborate on your canvas and share your documents through Drawboard Cloud – a new haven for PDFs. With a design that aims to replace traditional pen and paper, this application offers a comprehensive set of tools and an intuitive interface, making the transition to a paperless environment a straightforward choice for everyone. Embrace the future of document management today!

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.

UPDF provides a comprehensive solution for editing, annotating, and managing PDF files across platforms like Windows, Mac, iOS, and Android. This versatile application consolidates all essential tools into a single user-friendly interface, designed to cater to the preferences of both novice and experienced users who appreciate an aesthetically pleasing layout. Among its key features, UPDF allows users to edit PDF documents by adding, deleting, and modifying text properties, including font style, color, and size, while also enabling image manipulation such as cropping, rotating, and extracting. Additionally, users can annotate PDFs by highlighting, underlining, or striking through text, and can easily insert shapes, sticky notes, and text boxes for improved communication. Another significant feature is the ability to manage PDF pages, which includes options to rotate, delete, and extract specific pages as needed. Furthermore, UPDF enhances the reading experience by offering various viewing modes, including both single-page and double-page formats, ensuring flexibility for all types of users. With such a robust set of functionalities, UPDF stands out as an invaluable tool for anyone working with PDF documents.

Systweak PDF Editor offers an extensive range of features and tools designed for the editing and management of PDF files. Users can perform tasks such as redacting text, applying OCR to documents, signing files, splitting and compressing documents, converting several files simultaneously, and managing PDF security by locking or unlocking them, among other modifications. This comprehensive functionality positions it as an adaptable solution for individuals looking to work with PDFs in an efficient manner, catering to both personal and professional needs.

TinyWow provides an extensive selection of complimentary online tools focused on file conversion and PDF management, aimed at helping users tackle various tasks. To prioritize user confidentiality, any files—regardless of whether they have been processed—are deleted from the server within an hour. Users can effortlessly convert PDF documents into JPG images, enabling the download of each page as a separate image file. Likewise, TinyWow allows for the conversion of PDF files into PNG format, with each page also available for individual image downloads. This functionality makes TinyWow a practical and adaptable choice for anyone seeking swift and effective file conversion solutions, catering to diverse needs and preferences. Additionally, the user-friendly interface enhances the overall experience, making it accessible for individuals with varying levels of tech-savviness.

With Able2Extract Professional, you can handle various tasks such as converting, creating, editing, and signing PDFs, as well as utilizing OCR capabilities for scanned documents. The software allows for customization of the interface's language and visual style, offering both light and dark themes to enhance your PDF experience. You have the flexibility to select specific elements like pages, paragraphs, or lines for conversion, and can transform intricate PDF table data into Microsoft Excel format while preserving the original table layouts through the Smart Layout Detector feature. Additionally, you can modify PDF text and pages, annotate documents, and remove unwanted content. The program also supports signing PDF files, filling out forms, and creating new PDFs, while offering options to split documents into smaller sections. It enables the conversion of scanned PDFs into multiple languages, including English, French, and Spanish. For those managing large quantities of files, batch PDF conversion can be streamlined by organizing numerous documents into queues or entire folders, allowing for efficient processing. Moreover, you can batch create PDFs from diverse formats and merge them into a single document, while also securing your files by adding passwords and permissions. Able2Extract Professional truly serves as your all-in-one solution for comprehensive PDF management, catering to a wide range of user needs.

PDFgear is a comprehensive PDF tool that enables users to view, edit, convert, sign, annotate, and organize their documents seamlessly across Windows, MacOS, and iOS platforms. With its intuitive and user-friendly interface, PDFgear ensures a smooth experience for reading and editing documents without any distractions. The PDFgear Copilot serves as an advanced personal assistant that surpasses the capabilities of a typical document assistant, utilizing AI technology to help users navigate all features of PDFgear and interact with their PDF files. If you find yourself overwhelmed by the multitude of functions or content within your documents, simply reach out to Copilot for assistance—it's there to answer any questions you might have! Working with PDFs feels effortless and enjoyable with PDFgear, making your tasks as pleasant as a leisurely walk through a beautiful garden. Explore the full potential of your PDF documents effortlessly with this innovative tool!

Slim PDF Reader allows you to copy and paste text from PDFs, annotate them, and fill out interactive forms seamlessly. This lightweight and entirely free application offers the ability to validate digital signatures on various operating systems, including Windows, Mac, and Linux. Its Dark theme is designed to conserve battery life and minimize eye strain for users. With a minimal download size of just 15 MB, Slim PDF Reader is a fast, resource-efficient desktop PDF reader that remains completely free of any unwanted bloatware. You can experience an effortless PDF management solution that prioritizes user convenience and system performance.

SignFlow offers a simple yet effective solution for managing PDF documents, revolutionizing how you read, annotate, edit, sign, organize, and fill out secure files with ease. With a robust suite of essential tools at your disposal, SignFlow serves as the perfect ally for all your PDF-related tasks. You can effortlessly add legally-binding digital signatures to your documents, while also benefiting from a user-friendly interface for creating, editing, and completing forms. Enjoy intuitive text editing much like word processing, which allows for smooth management and modification of PDF pages, as well as easy annotation and viewing of your files. The platform boasts various reading modes, including Full-Screen, Single Page, Read Mode, Split View, and Multi-tab, ensuring maximum convenience for users. Navigate pages seamlessly and switch between day mode, night mode, and a special eye-protection mode to protect your eyes during extended reading periods. Make your notes pop by using highlighting, underlining, and strikethrough options to draw attention to key information within your PDFs. You can select from an array of colors to highlight different sections, ensuring clarity and emphasis. Furthermore, enhance your PDFs with standard business stamps like APPROVED, along with customizable text/image stamps for a polished presentation. For both professional and personal endeavors, SignFlow is expertly designed to elevate your PDF experience, simplify your workflow, and increase productivity. By incorporating these powerful features, SignFlow ensures that every PDF interaction is smooth and efficient, making it an indispensable tool in your digital toolkit.

Xodo provides the capability to edit, annotate, and sign PDF documents seamlessly across desktop, mobile, or web platforms. This user-friendly tool simplifies PDF management, eliminating the hassles of printing or faxing altogether. Now, you can easily sign important documents like contracts, expense reports, and cover letters directly on your smartphone or tablet, using just your finger or a stylus. The process is incredibly straightforward! With Xodo, signing any document requires merely a tap, freeing you from the hassle of searching for a pen or dealing with messy ink. You can also conveniently save your signature for future use, allowing you to sign documents with just a single tap or mouse click. Once you're done, saving and sharing the file with others is a breeze, significantly reducing the time spent in email exchanges. Xodo effectively alleviates the stress associated with completing forms. Using your smartphone or tablet, you can fill out forms from virtually anywhere by simply tapping on the screen and selecting checkboxes. This innovative approach allows you to save both time and effort, making it easier than ever to fill out and share forms on the go. With Xodo, managing your paperwork has never been more efficient or hassle-free!

Wondershare HiPDF is an innovative online PDF tool enhanced with AI capabilities, offering an extensive array of functionalities, including chatting with PDFs, AI reading, editing, converting, OCR, signing, and managing PDF documents, along with various image editing tools. The platform is user-friendly and comes with a free plan, enabling users to effortlessly summarize, explain, rewrite, merge, split, compress, convert, rotate, unlock, and secure PDF files in just a few clicks. As a recognized member of the PDF Association and holder of esteemed certifications like ISO 27001 and SSI SECURE, HiPDF prioritizes both ease of use and security, having successfully processed millions of documents to date. Highlighted Features: AI reading: Engage with PDFs through summarization, rewriting, explanations, and interactions with the AI PDF reading assistant. Document Conversion: Seamlessly convert PDF files to and from various Microsoft Office formats or images. PDF Merging: Effortlessly combine multiple PDF documents online. Size Compression: Easily reduce the size of PDF files through an online platform. Electronic Signing: Fill out and sign PDFs securely from any device at any time. PDF Protection: Safeguard sensitive information by restricting copying, editing, printing, and viewing with password protection. Overall, HiPDF stands out as a comprehensive PDF solution that balances functionality with user security.

CoolNew PDF is a versatile software designed to handle various aspects of PDF document management. It offers a range of functionalities such as editing, converting, splitting, merging, annotating, and securing your files, providing just a glimpse of its capabilities. The application's sleek interface is not only visually appealing but also user-friendly, allowing for easy navigation. By utilizing the ribbon menu, users can explore different categories of features effortlessly. Each section of the ribbon is accompanied by its own dedicated toolbar, offering tools tailored to the specific tasks listed. CoolNew PDF supports the export of most Office documents to and from PDF formats, and this capability extends to images as well. While merging, splitting, and extracting pages and images are fundamental features for any PDF management tool, they remain crucial for effective document handling. Additionally, users can effortlessly add watermarks and encrypt files for enhanced security, and the integrated OCR tool simplifies text extraction from images, ultimately saving valuable time. The software stands out as a comprehensive solution for all PDF-related needs.

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.

Streamline your document evaluations and effortlessly reveal insights while identifying connections that others might miss. LiquidText goes beyond conventional paper techniques, as the methods for note-taking and document examination have remained mostly static, relying heavily on margin annotations, highlights, and sticky notes that have been in use for a long time. Even with the emergence of digital applications, a notable portion—more than 80%—of knowledge professionals still prefer paper in their work and study environments. LiquidText, however, breaks free from these constraints by skillfully capturing your reading materials, notes, highlights, and annotations, while also illustrating the links between them and the original content. This cutting-edge tool presents your project components in an organized and easily shareable manner, allowing for a smooth connection between related notes and concepts. With just a single tap, you can visualize these relationships and revisit the original context, simplifying the process of crafting detailed reports based on your insights. By revolutionizing your engagement with documents, LiquidText not only enhances your efficiency but also fosters greater creativity in your work. Ultimately, this powerful tool enables you to harness your knowledge more effectively and transform how you approach your tasks.

LightPDF was designed to simplify the handling of PDF documents for users of all levels. With its user-friendly interface, this software enables individuals to effortlessly read, edit, and convert PDF files. The integrated editing features of the program include: 1. Editing capabilities: You can modify your PDF by adding text, annotating, and inserting hyperlinks, as well as incorporating headers or footers. 2. Conversion options: Easily convert PDF files into formats like Word, Excel, PPT, or JPG. 3. Page management: You have the ability to insert or delete pages, rotate them, and perform actions like extracting, replacing, splitting, or merging pages. 4. Signing features: Users can add either a handwritten signature or a digital signature to their PDFs. 5. Security measures: Protect your documents by adding a password to lock your PDF files. 6. Additional functionalities: The software also includes features such as OCR for text recognition, PDF compression, and background addition, among others, making it a versatile tool for various PDF needs.

Discover an innovative online platform specifically created for managing annotations from PDFs and Kindle, aimed at significantly reducing the time spent on tedious tasks. You can quickly download your annotations from both PDFs and Kindle in various formats in a matter of seconds. Our service adeptly summarizes annotations from PDF documents, Kindle books, and Instapaper articles, thus relieving you of the hassle of finding an effective annotation management tool. Sumnotes distinguishes itself as a user-friendly yet robust option for extracting annotations from diverse sources, including PDF books, lecture notes, and research papers, enabling you to focus on what is truly important. By simply clicking a button, you can import and sync annotations across multiple platforms effortlessly. Moreover, our batch import functionality allows for the convenient addition of your entire library in one go. We proudly accommodate PDF files annotated with any recognized PDF software, such as Adobe and Preview on Mac systems, and we are excited to introduce our new feature that supports Kindle highlights as well! This tool is set to revolutionize how you engage with your reading materials, making your annotation process smoother and more efficient than ever before. It's time to take control of your annotations like never before!

DeftPDF is a comprehensive online PDF editor that eliminates the need for subscriptions or installations, enabling users to effortlessly edit and convert their PDF documents in just a matter of clicks. This user-friendly tool streamlines the process, making PDF manipulation accessible to everyone.

The PDF Converter application enables users to swiftly transform any file on their iPad into a PDF document. It allows for easy access and downloading of files from emails, cloud storage, or the internet directly on the device, quickly converting them into visually appealing PDFs. This app is specifically tailored for its purpose and excels in delivering high-quality results. Whether you’re dealing with a multi-million dollar contract or a simple webpage, you can save it as a PDF in mere seconds. The PDF Converter is adept at generating high-quality PDFs from a diverse range of file types, including email attachments, iWork and MS Office documents, images, web pages, and more. Once your PDF is created, you can leverage the powerful features of PDF Expert to view, annotate, edit, or merge your documents effortlessly. The accuracy of the conversion process ensures that the original content is preserved perfectly, giving users complete control over the entire experience. Moreover, the app guarantees total security by performing all conversions locally on the iPad, eliminating the need for an internet connection and ensuring that your files remain confidential. This feature also enhances convenience for users who may not always have internet access, allowing them to work efficiently at any time. Ultimately, the PDF Converter app stands out as an essential tool for anyone looking to streamline their document management on the go.

MiniTool PDF Editor provides a comprehensive solution for editing all your PDF documents effortlessly. It enables users to transform files into various formats, merge several documents into one cohesive file, divide a single document into multiple parts, and enhance the content with a range of annotation tools. This versatile software allows seamless conversion of PDF files into numerous formats, including Microsoft Word, Excel, and PowerPoint, as well as image formats like JPG, PNG, and BMP. Additionally, it supports TXT, HTML, EPUB, CAD, and XPS conversions, and any file type can also be converted back into PDF format. For instance, an ordinary image can be transformed into a PDF in mere seconds, and the same applies to spreadsheets. MiniTool PDF Editor stands out as a user-friendly application that simplifies the process of PDF modification. With its intuitive interface, you will find all its features accessible and easy to navigate, making your document management tasks much more efficient.