What is MuPDF?

MuPDF is a fast, lightweight, high quality PDF viewer for Android devices.

It’s fast and lightweight which allows it to be more efficient, and use less memory. MuPDF's renderer is designed to produce high-quality, anti-aliased graphics. For the utmost degree of accuracy in simulating the appearance of a printed page on the screen, it displays text with metrics and spacing accurate to fractions of a pixel.

This is achieved through a custom rendering engine that’s tailored for Android. 

The result is a PDF viewer that’s fast, efficient, and suitable for most use cases.

It can also be used as a viewer for XPS and EPUB files.