When comparing Sumatra PDF vs Adobe Reader, the Slant community recommends Sumatra PDF for most people. In the question“What are the best PDF readers?” Sumatra PDF is ranked 1st while Adobe Reader is ranked 7th. The most important reason people chose Sumatra PDF is:
Sumatra is available for free, licensed under GPL with source code available on [GitHub](https://github.com/sumatrapdfreader/sumatrapdf).
Ranked in these QuestionsQuestion Ranking
Pro Free and open source
Sumatra is available for free, licensed under GPL with source code available on GitHub.
The application consists of a single file that can be run without installation. You can put it on an external device, such as an usb thumb stick and run it on any Windows machine from the thumb stick.
Pro Extensive keyboard shortcuts
It's available in 69 languages.
Pro Elegant interface
Pro Low resource usage
Pro Starts quickly
Pro Best in class compatibility with the PDF standard
Since Adobe is the creator of the PDF standard, it stands to reason that Adobe's Acrobat Reader has the best support for it.
Pro Allows comparing two separate PDF files for differences
Reader can compare two versions of a PDF file and highlight differences.
Pro Integrated cloud service
Gives access to a cloud service that allows storage and sharing of PDF files.
Con Lacking in features
Sumatra aims for simplicity at the expense of functionality. For example, there's no way to annotate PDFs or edit them.