Sumatra PDF: Lightweight Free Reader for PDF, EPUB and More

Sumatra PDF starts quickly and stays out of the way. It has no ribbon, no account and no cloud features; it simply opens documents and lets you read them.

Formats it opens

Besides PDF, Sumatra reads EPUB and MOBI eBooks, XPS documents, DjVu scans, CHM help files and CBZ/CBR comic archives. That makes it a single viewer for most of the reading files that collect on an office PC.

Choosing a build

1. The Download button opens the official download page on sumatrapdfreader.org.
2. Pick the architecture: 64-bit for almost all modern PCs, ARM64 for Windows on ARM laptops, or 32-bit for old systems.
3. Choose the installer, or the portable .zip containing a single .exe that runs from a USB stick and writes nothing to the registry.

The 64-bit and 32-bit builds support Windows 7 to 11, while the ARM64 build needs Windows 10 or 11. An older version is still offered for Windows XP and Vista.

What it does not do

Sumatra is a reader, not an editor. It can add simple annotations to PDFs, but it does not fill in complex forms well, merge files or edit text. Keep Foxit PDF Reader or Adobe Acrobat Reader around for forms, and use PDFsam Basic for splitting and merging.

Open source

The source code is on GitHub, and the program is free with no ads. For a large eBook library with conversion tools, pair it with Calibre.