Best Web-Based PDF Annotators of 2025

Apryse, formerly PDFTron, is reimagining the world of documents. Bring accurate PDF viewing, annotating, editing, creation, and generation to any web, mobile, desktop or server framework or application. Apryse technology supports all major platforms and dozens of unique file types, including support for PDF, MS Office, and CAD formats. Own the full document and data lifecycle by deploying on your own infrastructure without worrying about third-party server dependencies.

Nutrient provides an extensive solution for all your PDF requirements, delivering tools that seamlessly operate PDF features across any platform. 1. SDK: Incorporate advanced PDF functionality into iOS, Android, Windows, web, or any cross-platform technology, supplying abilities like PDF viewing, annotation, collaboration, and beyond. 2. Libraries: Employ our powerful .NET and Java libraries to enhance your backend applications with batch processing of redactions and PDF forms, OCR'd scanned text, and PDF document editing, all directly from your application server. 3. Processor: Our agile PDF microservice, Processor, enables rapid generation of PDFs from HTML, including HTML forms, as well as Office-to-PDF conversions, OCR, redaction, and XFDF combining and exporting. 4. PDF API: Take advantage of our hosted PDF API to generate, convert, and alter PDF documents in your workflows. We handle the development and server management, freeing you up to concentrate on your business. At Nutrient, we're not just a tool; we're a committed ally in your success. Gain direct contact with our engineers for expert guidance, utilize comprehensive examples to simplify integration, and make the most of our top-tier documentation.

Global OEMs, SaaS and enterprise end-users rely on Adobe PDF Library to automate the creation, editing and management of PDFs. An Adobe partner, our SDK uses the same source code as Acrobat for stability, reliability and quality results. Languages: .NET, .NET Framework, Java and C/C++ Platforms: Windows, Linux & MacOS Package managers: NuGet & Maven Capabilities include but are not limited to: -Annotations -Content creation -Content modification -Color management -Extraction - text, images, forms -Compression/optimize -Conversion - PDF/A, PDF/X, EPS, PostScript, XPS, ZUGFeRD, color -Display, Printing -Extract text, images & other content -Forms - Import, export, flatten static & dynamic XFA forms, AcroForms -Images - extract, import/export, thumbnails, render/rasterize pages, separations -Optimization - size, content, images, etc. -OCR - add text to document, add text to image -PDF to Office Documents (Word, Excel, PPT) -Security - Viewer settings, redactions, password, encrypt/decryption, watermark Pricing options for OEMs, SaaS & end-users are flexible and based on usage. Shorten development times & get to market faster with Adobe PDF Library. Free trial - download today.

MobiPDF (formerly PDF Extra) is an intuitive reader and editor that allows you to read, edit, create, OCR, organize, annotate, fill and sign, convert, and share any PDF. This makes MobiPDF an excellent choice for users seeking a budget-friendly alternative to Adobe Acrobat Pro. HERE’S WHAT YOU GET WITH MOBIPDF: Multiple Page View Modes: Enjoy a distraction-free "Read Mode". Advanced Editing Tools: Experience a Word-like PDF editing environment. Two-Way Conversions: Convert PDFs to and from Word, Excel, PowerPoint, or image formats. OCR Support: Make scanned documents searchable. Markup Tools: Highlight, comment, strikethrough, stamp, and more to enhance your documents. Effortless PDF Organizer: Reorder, compress, split, and combine PDFs with ease. Sign & Secure: Add signatures, create and fill forms, and protect your PDFs with passwords, encryption, and digital certificates. Offline Mode: Work freely on your projects, even offline. Seamless translation: One-click translate any PDF into 50+ languages.

SwifDoo PDF is an All-in-One PDF Maker, Reader, Editor and Converter for Windows SwifDoo PDF enables users to create, convert, merge, compress and sign PDF documents with minimum effort. The intuitive design tool also enables you to insert links or images to PDFs. The PDF document can be converted to Microsoft Word, Excel, PowerPoint, JPG, PNG, TIFF, BMP, and vice versa. You can also convert CAD to PDF. The PDF compression module integrated with SwifDoo PDF is optimized for file size without quality loss. SwifDoo PDF has a number of special features for scanning copy convert. Besides many convert features. PDF Reader PDF Annotation (Including Stamp) Picture/image Extraction (only need copy and paste from PDF) PDF Edit PDF Compress PDF Merge PDF Split PDF Signature System Requirements: Windows 10/7/8/vista/XP Edition: SwifDoo PDF 2.0.1.9

Install-free PDF editing, form filling, redaction, signing, viewing, and more on your website with RAD PDF! Packaged as an easy to use library / WebControl (compatible with .NET 3.5+, .NET Core, and .NET 5+), RAD PDF can be used with just about any flavor of ASP.NET including MVC, Razor, Blazor, WebForms, and more. RAD PDF is compatible with 99% of internet browsers, including those on Linux, Mac OS X, Microsoft Windows, and mobile. No plugins. No Adobe Reader. RAD PDF is more than a PDF to HTML converter. It natively supports all the most common PDF features including annotations, bookmarks, form fields, page labels, and more. With advanced PDF options, RAD PDF allows you to selectively enable and disable features not available with Adobe Acrobat Reader, like protecting a PDF from being downloaded while still viewable online. RAD PDF users can use PDF form fields directly from the web browser by enabling PDF form filling and PDF form saving without having to install any software. Integrating directly with ASP.NET, RAD PDF allows your web application to capture input data, build custom workflows, and provide an intuitive graphical user interface (GUI) for just about any online PDF interaction imaginable!

PDF Tools for you to be more productive with PDF documents. Free and easy to use! Add text, images, freehand annotations to PDF. Fill forms. Create your own signature and sign document. Send PDF files safely and securely with a link that automatically expires, zero-knowledge end-to-end encryption with 256-bit AES.

Easily convert, edit, merge, and compress your PDF files with just a few simple clicks. You can quickly download your document without any hassle, as our PDF converter generates files in mere seconds! To ensure the safety of your digital information, we implement HTTPS encryption while you create PDF files on our site. You can redact PDFs, alter text, insert new elements, and engage in various other tasks, all from a single platform. Our user-friendly interface is designed for seamless navigation, allowing you to utilize our PDF creator with minimal effort. Compatible with every major operating system, our online PDF maker functions flawlessly on Windows, Mac OS, Linux, iOS, and Android. For those who wish to maintain privacy, you have the option to secure your file by locking or restricting access, preventing others from opening, editing, or printing it. This comprehensive tool simplifies your document management and enhances your productivity.

Experience the convenience of viewing, signing, collaborating on, and annotating PDFs with the complimentary Adobe Acrobat Reader. With Adobe Acrobat Reader, you have the unique ability to view, sign, gather and monitor feedback, and share PDFs at no cost. For those seeking expanded functionality, a subscription to Acrobat Pro allows for editing, exporting, and sending PDFs for signatures. Go beyond merely opening and reviewing PDF documents; easily annotate files and consolidate comments from various reviewers in a single, shared online PDF. The Acrobat Reader mobile app empowers you to manage documents on the go, equipped with essential tools for converting, editing, and signing PDFs. You can even utilize your device's camera to capture images of documents, whiteboards, or receipts and save them as PDFs. Acrobat Reader seamlessly integrates with Adobe Document Cloud, enabling you to access and work on your PDFs from virtually anywhere. Furthermore, you can conveniently store and access your files through platforms like Box, Dropbox, Google Drive, or Microsoft OneDrive, enhancing your document management experience. Whether you're in the office or on the move, Acrobat Reader ensures you have everything necessary to handle your PDF needs effectively.

Regardless of whether you are a consumer, a business, a governmental body, or an educational institution, it is essential to read, create, sign, annotate, and fill out PDF forms. Foxit PDF Reader stands out as a compact, incredibly fast, and feature-packed PDF viewer that enables users to create PDFs for free, as well as open, view, sign, and print any PDF document. This software is powered by the fastest and most precise PDF rendering engine in the industry, ensuring an exceptional PDF viewing and printing experience for all users. It offers support in multiple languages, including English, Dutch, French, German, Italian, Portuguese, Russian, and Spanish. Users can sign documents using their own handwriting, take advantage of eSignature functionalities, and easily verify the status of digital signatures. To safeguard against potential vulnerabilities, Foxit PDF Reader incorporates features like Trust Manager/Safe Mode, ASLR & DEP, the ability to disable JavaScript, and Security Warning Dialogs. Additionally, it seamlessly integrates with major cloud storage services and widely used enterprise content management systems, making it an invaluable tool for organizations of all types. Its versatile capabilities make it a preferred choice among users looking for reliability and efficiency in managing PDF documents.

PDF.live allows you to convert PDFs into any other file format and vice versa. Convert Word documents, Excel sheets, PowerPoint presentations, and JPEGs. PDF.live works on any device connected to the internet and is cloud-based. This means that you don't have to download or install anything. Simply drag the document and follow the prompts to sign, annotate and edit text. You can also compress, merge, and compress your documents with this free online PDF editor.

UPDF allows you to edit, annotate, and manage PDF on Windows, Mac, iOS, Android, and Android. All the tools you need to organize, edit, annotate and manage your PDF files are available in one smart, all-rounder smart app. It was specifically designed to satisfy the needs of most users who want a beautiful yet easy-to-understand interface that is not only for beginners. Key Features 1. Edit PDF Document You can add, delete, and edit text properties and formats, such as font style, font color and size. You can also crop and rotate, replace, remove, or extract images. 2. Annotate PDF - Highlight, underline, or strike out any parts. For a faster and easier way to add text, you can also add shapes, sticky note and text boxes. 3. PDF Page Management Rotate, delete and extract PDF pages. 4. Navigate and View PDF Files - Flexible reading mode, such as single-page mode or double-page mode.

TinyWow offers a variety of free online tools for conversion and PDF handling, designed to assist users with a wide range of challenges. To ensure privacy, all files, whether processed or not, are removed from the server within an hour. Users can easily transform PDF files into JPG images, allowing them to download each individual page as a separate image file. Similarly, it is also possible to convert PDF documents into PNG format, with each page available for download as an image as well. This makes TinyWow a versatile option for anyone needing quick and efficient file conversions.

Add robust PDF features to your apps with the easy-to-integrate MuPDF SDK/ The small yet fast viewer supports a number of document formats including PDF, XPS, OpenXPS, CBZ, and ePUB. The renderer is designed for high-fidelity anti-aliased graphics and renders text with metrics and spacing accurate to within fractions of a pixel. The PDF library includes interactive features such as annotations, form filling, digital signatures, redactions, and search. The command-line tools provide users myriad customization options for rendering and converting documents, and manipulating PDF files. MuPDF supports document conversion to other formats including HTML, SVG, and CBZ. In addition to the C library, there's a Java library using JNI that works for both Oracle's Java and Android. In addition to the Java API, C++ and Python bindings have been developed. MuPDF supports most of the major coding environments and operating systems. It is highly flexible and optimized for each unique platform. MuPDF API has been used as the PDF engine in a variety of deployments ranging from Android and iOS mobile applications, SaaS and cloud solutions, document management programs, and embedded products, to name a few.

PDFgear is a PDF solution that allows users to view, edit, convert, sign annotate, organize and more on Windows, MacOS and iOS. PDFgear's clean and simple interface allows users to enjoy reading and editing documents without interruption. PDFgear Copilot is a personal assistant that offers more options than a standard document assistant. It's powered by AI so users can easily manipulate all the PDFgear features and chat with PDFs. You're lost in the vast array of functions and document content? Don't worry! Ask Copilot! You can ask Copilot anything! Processing PDFs is as easy as a stroll in the garden with PDFgear.

Xodo allows you to edit, annotate and sign PDFs on your desktop, mobile, or web. Xodo makes it easy to work with PDFs. No more printing or faxing! You can sign contracts, expense reports and cover letters on your smartphone or tablet with just your finger or stylus. It's that easy! Sign any document with just your finger, instead of searching for a pen or printing ink. You can save your signature and sign any future documents with just one tap or click of the mouse. Save the file and share it with anyone who needs it. It takes only seconds to do what used to take many emails back and forth. Xodo takes stress out of filling out forms. You can complete forms from your smartphone or tablet anywhere you are by simply tapping on the screen to fill in fields and selecting checkboxes. You can save time and energy. Fill out forms on your smartphone or tablet and save them to share with anyone who needs them.

Wondershare HiPDF is an AI-powered online PDF solution that offers a wide range of features such as chatting with PDF, AI reading, editing, converting, OCR, signing and managing PDF documents. It also provides many image tools. HiPDF is easy to use and has a free plan. It allows users to easily summarize, explain, rewrite, merge, split, compress, convert, rotate, unlock, and protect PDF files with just a few clicks. As a member of the PDF Association and having received internationally recognized certifications such as ISO 27001 and SSI SECURE, HiPDF ensures both simplicity and security in editing PDFs, having processed millions of files cumulatively. Top Features: AI read: Summarize, rewrite, explain and chat with PDFs with the AI PDF reading assistant. Convert PDF: Convert PDF documents to and from any Microsoft Office format or image. Merge PDF: Combine PDF files online. Compress PDF: Reduce the size of your PDFs online easily. Sign PDF: Quickly and securely fill and sign PDFs from any device, anytime, anywhere. Protect PDF: Protect PDF from copying, editing, printing and viewing with passwords. Keep sensitive data confidential.

Conholdate.Total is the complete package for all.NET APIs offered by Aspose or GroupDocs. This allows developers to perform a wide variety of document processing tasks within their own.NET based apps. This.NET package provides all-in-one solutions for all types document management systems. It allows you to create, edit and print, view, sign, compare, sign, automate and convert between a variety of popular document formats. Conholdate.NET allows you to process a multitude of file formats. File formats can be opened, modified, converted, and modified easily. Conholdate.Total.NET currently supports the following file types: Microsoft Word documents Microsoft Excel spreadsheets Microsoft PowerPoint presentations Adobe PDF documents Microsoft Outlook Microsoft Project files More than 100 other file formats

LightPDF was created to make it easy for anyone to use PDF documents. LightPDF has an intuitive interface. This program allows you to read, edit, and convert PDF documents. Built-in PDF editing capabilities: 1. Modify a PDF: Add text, annotate and insert links. You can also add headers or footers. 2. Convert PDF to Word, Excel, PPT or JPG. 3. Manage PDF pages: Insert or delete pages, rotate pages and extract, replace, split, or merge pages. 4. Sign a PDF: Add a manual signature or digital signature. 5. Lock PDF: Add a password for your PDF document. 6. Other tools: OCR and compress PDF, add background, etc.

Generate and manage PDF files with ease by utilizing features such as splitting, appending, stamping, encrypting, extracting, and filling. PDFKit.NET is a fully managed .NET class library designed for the creation and manipulation of PDF documents, packaged as a single assembly that allows for straightforward xcopy deployment. It operates independently with no additional requirements beyond the .NET framework itself. At the heart of PDFKit.NET lies a coherent and user-friendly object model comprising various classes like document, page collection, page, canvas, shape, bookmark, annotation, and field. The development team's primary goal is to simplify the integration of this class library into larger applications. With PDFKit.NET 5.0, users can fill in text fields, checkboxes, and radio buttons, while also having the option to save the forms in either an editable state or as a flattened PDF. Additionally, this version introduces the ability to handle dynamic XFA documents through the new XFA processor API, enhancing functionality. Furthermore, PDFKit 5.0 enables users to extract all graphics from a page, compiling them into a collection of various shapes, which can include text, images, and curves, providing versatile options for document manipulation. This makes PDFKit.NET an invaluable tool for developers looking to incorporate robust PDF handling capabilities into their applications.

Experience a revolutionary online tool for managing your PDF and Kindle annotations, designed to save you countless hours of tedious work. Instantly download your annotations from PDFs and Kindle in multiple formats within seconds. Our service efficiently summarizes annotations from your PDFs, Kindle books, and Instapaper articles, eliminating the frustration of searching for an effective annotation tool. Sumnotes stands out as a straightforward yet powerful solution for extracting annotations from a variety of materials, such as PDF books, lecture notes, or research papers, allowing you to concentrate on what truly matters. With just one click, you can import and synchronize annotations across different platforms seamlessly. Additionally, our batch import feature makes it incredibly easy to bring in your entire library. We proudly support PDF documents annotated with any official PDF software, including Adobe and Preview on Macs, and we're thrilled to announce our new capability to support Kindle highlights as well! This tool is poised to transform the way you interact with your reading materials.

All-in-one online PDF editor, free of subscriptions and installations DeftPDF is an online tool that allows you to edit and convert your PDF files in just a few clicks.

SmartOffice allows you to view, edit, create and print Microsoft Office and PDF documents from your mobile device. SmartOffice PDF allows you to view, annotate and highlight PDF documents. Convert Office documents into PDF, save to your mobile device, or to a cloud account and print wirelessly to thousands supported printers. SmartOffice Mobile App This app is a full-featured alternative to MS Office 365. SmartOffice can be downloaded from GooglePlay or the AppStore for personal use. SmartOffice can also be wrapped in an enterprise security platform that will enable mobile productivity. SmartOffice SDK SmartOffice offers many solutions that can be seamlessly integrated into your enterprise document workflow platform. SmartOffice SDK seamlessly integrates with your EFSS or MDM environment. SmartOffice mobile app can also be wrapped in an enterprise security platform.

We offer comprehensive solutions for the processing, analysis, and conversion of documents, delivering cutting-edge innovations in document imaging and management. Our expertise in imaging technologies has been honed since 2003, allowing us to develop effective strategies for managing electronic documents, whether locally or through online platforms. The following highlights illustrate the advanced technologies utilized by ORPALIS: Full support for PDF files enables users to view, edit, annotate, compress, and sign PDFs seamlessly. Our TWAIN and WIA scanning capabilities facilitate the management of all types of scanners and acquisition devices. We also specialize in barcode reading and writing, supporting both 1D and 2D formats, including Datamatrix, QR-Code, Micro QR-Code, and PDF417. Our hyper-compression technology leverages mixed raster techniques, offering efficient content compression through Color Detection, JBIG2, and JPEG 2000 methods. Furthermore, we provide support for over 100 document formats, allowing users to view and convert documents with ease. Our Optical Character Recognition (OCR) technology allows for the extraction of text and MICR characters from scanned images, while our form and template recognition capabilities ensure accurate automatic document recognition and forms processing. Users can also annotate their documents using a variety of tools, both online and offline, enhancing collaboration and productivity in document management. Overall, our solutions are designed to meet the diverse needs of modern document workflows.

PDFKit is a versatile library designed for generating PDF documents in both Node and browser environments, facilitating the creation of intricate, multi-page, printable materials with ease. Its API promotes chainability and offers a combination of low-level functions alongside higher-level abstractions, making it user-friendly. With PDFKit, producing elaborate documents can often be accomplished through just a handful of function calls. It also encompasses access privileges, which include options for printing, copying, modifying, annotating, form filling, ensuring content accessibility, and document assembly. Accessibility features are well-supported, featuring marked content, a logical structure, Tagged PDF, and compliance with PDF/UA standards. Additionally, PDFKit is compatible with JPEG and PNG images, allowing for the use of indexed PNGs and those with transparency. Alongside PDFKit, it's crucial to have a destination to stream the generated output. For projects utilizing PDFKit through Browserify, it's important to install the brfs module via npm, which is essential for loading built-in font data into the library. This combination of features makes PDFKit a powerful tool for anyone looking to create detailed and professional PDF documents efficiently.