PDF4
PDF4 is an all‑in‑one mobile PDF toolkit for scanning, editing, converting, and securing documents directly on your device. It combines robust editing features, like modifying text, images, and pages, merging and splitting files, reordering or rotating content, with powerful conversion tools to transform images or Office formats into PDFs and vice versa (e.g., PDF to Word, PowerPoint, or Excel). It supports OCR for searchable text extraction, password protection, annotations, and form filling. Users can compress files, crop pages, add metadata, watermarks, or barcodes, and leverage automation such as job‑flows for batch processing on a desktop. Extended integrations include browser extensions, Zapier/Power Automate connectors, and Microsoft Teams/Outlook add‑ins, enabling seamless PDF workflows across platforms.
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Adobe PDF Library SDK
4.5 out of 5 stars
(6 Ratings)
Adobe PDF Library is the only commercial PDF SDK built on Adobe Acrobat's own core engine, delivering the same rendering accuracy, PDF spec coverage, and behavior as Acrobat itself.
Available in Modern C++, Adobe C/C++, .NET, .NET Framework, and Java, and supported on Windows, macOS, and Linux. Create, edit, merge, split, annotate, and watermark PDFs programmatically; convert to and from Word, Excel, PowerPoint, PDF/A, PDF/X, and more; add OCR, digital signatures, redaction, and encryption; and process AcroForms and XFA forms.
SOC 2 Type 2 compliant, with a 91% customer retention rate among enterprise users.
For enterprise deployment, the pdfRest API Toolkit Container packages this technology as a self hosted REST API for on premises, private cloud, or hybrid environments.
Datalogics also offers Scout, an AI assistant, and an MCP server so teams can bring PDF capabilities into AI powered workflows.
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FixMyPDF
FixMyPDF is a privacy-first, free online PDF toolkit offering 70+ tools to convert, organize, secure, optimize, and edit PDF files. All processing is 100% browser-based—no file uploads, no registration required, and no data tracking. Features include compressing PDFs, converting images (JPG, PNG, SVG, etc.) to PDF and vice versa, editing metadata, adding or removing password protection, splitting & merging, text extraction, watermarking, annotation editing, and much more. Used by over 10,000 users and processing 100,000+ files with a 4.9★ rating.
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DeftPDF
An all-in-one free online PDF editor that does not require subscriptions or installations! DeftPDF is a free online tool that makes editing and converting easy in just a few clicks! Our servers process the files for you. Files stay secure. After processing, they are permanently deleted. Use the PDF editor to edit & sign PDF files online for free. You can also fill out PDF forms online, change or add text on a PDF, edit existing PDF text, add images, create links or edit hyperlinks, and annotate in your PDF document. You can be assured that your files are safely uploaded over an encrypted connection. The files will permanently be deleted after processing. To upload files from Dropbox, Google Drive or from a website where your files are located, expand the drop-down list and select your files. You can edit any existing text on the document and change fonts or format such as bold, italic, size and color.
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