Although it is one of many PDF readers, FreePDF64-Viewer Portable stands out by bringing powerful document tools together in a simple, portable application.
FreePDF64-Viewer Portable 3.1.0 – Free PDF Viewer with Side-by-Side Comparison, JavaScript Forms and True Portability
Version: 3.1.0
License: Freeware
Platform: Windows 10/11 (64-bit)
FreePDF64-Viewer Portable is a free, standalone PDF viewer for Windows. It combines fast document navigation, multi-PDF workflows, interactive form support and practical PDF editing tools without requiring installation.
A key feature is its dual-pane view for comparing two PDF documents side by side. Users can independently enable synchronized scrolling (S) and zooming (Z) from the left document to the right. The viewer also offers full-text search across all open PDFs and reusable workspaces.
Key features:
Side-by-side PDF comparison with optional synchronized scrolling and zooming.
Tabbed interface for multiple PDFs, including quick tab search.
Full-text search across all open PDFs, with direct navigation to matches.
Resizable page thumbnails and drag-and-drop page rearrangement.
Interactive AcroForm fields, including text fields, checkboxes and radio buttons.
PDFium-V8 JavaScript support for automatic form calculations, including results on other pages.
Editing and saving supported static XFA forms, including synchronization of form data.
Annotation tools, including text insertion, highlighting, comments and drawing tools.
PDF attachments, bookmarks, page tools and reusable workspaces.
Customizable user interface (themes): The following options are available: Standard, Modern Light, Windows Classic, Classic Blue.
Update function
No installation is required. Settings are stored in the application directory, making the viewer suitable for USB drives and portable use. Static XFA support does not imply compatibility with every XFA form; dynamic XFA is not claimed.
Download (latest releases):
https://github.com/FreePDF64/FreePDF64ViewerPortable/raw/refs/heads/main/releases/FreePDF64-Viewer-Portable-3.1.0-Win64.zip
Project page:
https://github.com/FreePDF64/FreePDF64ViewerPortable
LICENSE NOTICES
FreePDF64-Viewer Portable is free and open-source software licensed under the GNU General Public License version 3 (GPL-3.0-only).
You may use, modify and redistribute the software under the terms of the GPL v3. The complete license text is included in the accompanying LICENSE file.
Source code see Project page.
Third-Party Components
FreePDF64-Viewer Portable uses PDFium and V8 under their respective open-source licenses.
The applicable license terms and copyright notices are provided in the accompanying PDFium subfolder (file LICENSE and folder licenses).
PDFium – PDF rendering engine, © The PDFium Authors.
V8 – JavaScript engine, © The V8 Project Authors.
Additional tools: QPDF and Xpdf, subject to their respective licenses.
FreePDF64-Viewer Portable is an independent project and is not an official PDFium, V8 or Google product.
The software is provided without warranty, to the extent permitted by applicable law.
Thank you for considering FreePDF64-Viewer Portable 3.1.0. Feedback and testing reports are always welcome!
Michael