The best open source alternative to Adobe Acrobat Reader is SumatraPDF. If that doesn't suit you, our users have ranked more than 100 alternatives to Adobe Acrobat Reader and loads of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Adobe Acrobat Reader are Okular, Xournal++, Stirling PDF and MuPDF.
This free, open-source viewer for Windows supports multiple formats like PDF, eBooks (ePub, Mobi), CHM, and Comic Books (CBZ, CBR). Prioritizing simplicity and speed, it offers a lightweight, portable design with a minimalist interface, catering to users seeking fast and efficient document viewing.
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Multi-platform document viewer supporting PDF, ePub, comics, images, and Markdown with annotation, digital signature verification, tabbed interface, sidebar navigation, text selection, text-to-speech, magnifier, search, dark mode, and plugin support.
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Handwritten note-taking and PDF annotation using pen input and pressure sensitivity, shape drawing, customizable toolbar layouts, image insertion, audio recording, multi-language options, LaTeX integration, and complete export in PDF or PNG formats across all platforms.
Locally hosted web application offering an interactive GUI to merge, split, reorganize, convert, compress, watermark, secure, sign, flatten, repair, extract images, detect blanks, apply OCR, set permissions, and enable file processing or API integration for PDFs.
United States
MuPDF offers a highly versatile PDF, XPS, and eBook interpreter, customizable as a renderer, viewer, or toolkit. Features include digital signatures, redactions, form filling, annotations, and page manipulation, ideal for mobile, eBooks, and embedded apps supporting Java, C++, and Python.
United States
Supports viewing and editing PDF annotations, displays multiple formats such as PDF, Postscript, DjVu, comic books, TIFF, DVI, XPS, remembers per-document zoom and position, features search, table-of-contents navigation, SyncTeX integration, and printing.
United States
PDF Viewer (aka pdf.js) is a new revolutionary extension using web standard technologies that allows you to display within Mozilla Firefox almost all PDF files found on the web without a plugin.
United States
Butterfly is a note-taking app where your ideas come first. You can paint, add texts, and export them easily on every device. This app works on android, windows, linux, and in the web.
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High-performance viewer for documents and images offering split tabs, customizable single or book layouts, portals for side-by-side sections, instant search, line highlight, annotation tools, link hints, searchable highlights, session management, and TOML config.
SpainEU
Sioyek is a PDF viewer with minimal interface optimized for reading research papers and technical books.
United States
PDF viewer for macOS supports scientific papers, annotations, highlights, bookmarks, split view, exporting notes, AppleScript, multiple annotation types, bibliography integration, full-screen, search, and compatibility with various macOS versions.
