MuPDF viewer

MuPDF is the PDF and document engine of Artifex Software, the company that also makes Ghostscript, and it is used inside many other apps, including Librera Reader. MuPDF viewer is Artifex’s own small Android app around it. The README describes it as “a simplified variant of the full MuPDF Android app that only supports viewing documents”. New versions follow each MuPDF release; 1.28.5a came out in September 2026. Artifex also publishes an even more minimal app, MuPDF mini.

What it does

• Opens documents through Android’s file picker, or from another app with Open with: PDF, XPS and OpenXPS, EPUB, MOBI, FB2 and CBZ comic archives.
• Reading: pinch to zoom; tap near an edge to move back or forward, and in the middle to show the toolbars. A slider and a page counter at the bottom.
• Search with highlighted hits, and the table of contents when the document has one.
• Password-protected PDFs ask for the password.
• Text size for EPUB, MOBI and FB2, which are laid out to fit the screen.
• It remembers the page you were on in each document.

To stay small, the Android build leaves out MuPDF’s own fallback fonts and uses the phone’s system fonts when a document doesn’t embed its own. Files up to 8 megabytes are read into memory, larger ones as needed. The menus are in English only.

What it doesn’t do

It is a viewer and nothing else: no annotations, form filling, text selection or copying, saving, printing or sharing, no night mode, no continuous vertical scrolling and no jump to a page number. F-Droid’s description says MuPDF supports “annotations, searching, form editing and more”; that describes the engine, not this app.

Two open bug reports to know about: on EPUB files the remembered page can drift further on each reopening, and the page slider can disappear and not come back.

What goes online

Nothing. The app declares no internet permission and contains no analytics or crash-reporting code. A web link you tap, once links are switched on, is handed to your browser.

About this file

• This is F-Droid’s build of version 1.28.5a, compiled from Artifex’s tagged source, with the MuPDF library also built from source rather than downloaded ready-made from Artifex, and signed with F-Droid’s key. The Google Play version has the same package name but another key, so neither updates the other. Artifex offers no APK download of its own.
• The 17.1 MB file runs on Android 5.0 and later, on ARM, 32- and 64-bit, and on 32-bit x86. It declares 1 permission, reading storage, which the code never asks for; files reach it through the file picker or Open with, so it most likely reads only the documents you open in it.
• MuPDF viewer and MuPDF are licensed under the AGPL-3.0 or later. Artifex sells commercial licences to developers who build MuPDF into products that can’t meet the AGPL; that doesn’t concern using the app. The engine includes open-source libraries such as FreeType, HarfBuzz, OpenJPEG and zlib.
• F-Droid has no screenshots for this app; ours are from its Google Play listing, which doesn’t say which version they show.

CPU types in this build: arm64-v8a (64-bit ARM, almost every phone since 2017); armeabi-v7a (32-bit ARM, older and budget phones); x86 (32-bit Intel, emulators).

Versions currently kept in the F-Droid repository. We host and check only the newest one. Full changelog.