NAME

       zipalign - ZIP/APK alignment tool for Android application files

SYNOPSIS

       To align infile.zip and save it as outfile.zip:

       zipalign [-f] [-p] [-v] [-z] align infile.zip outfile.zip

       To confirm the alignment of existing.zip:

       zipalign -c [-p] [-v] align existing.zip

       The  align  is  an integer that defines the byte-alignment boundaries.  This must always be 4 (which pro‐
       vides 32-bit alignment) or else it effectively does nothing.

DESCRIPTION

       zipalign is an archive alignment tool that provides important optimization to Android application  (.apk)
       files.   The  purpose is to ensure that all uncompressed data starts with a particular alignment relative
       to the start of the file.  Specifically, it causes all uncompressed data within the .apk, such as  images
       or  raw files, to be aligned on 4-byte boundaries.  This allows all portions to be accessed directly with
       mmap() even if they contain binary data with alignment restrictions.  The benefit is a reduction  in  the
       amount of RAM consumed when running the application.

       This  tool should always be used to align your APK file before distributing it to end-users.  The Android
       build tools can handle this for you.  Android Studio automatically aligns your APK.

       Caution: You must use zipalign at one of two specific points in the app-building  process,  depending  on
       which app-signing tool you use:

       • If you use apksigner, zipalign must only be performed before the APK file has been signed.  If you sign
         your APK using apksigner and make further changes to the APK, its signature is invalidated.

       • If you use jarsigner, zipalign must only be performed after the APK file has been signed.

       The  adjustment  is made by altering the size of the “extra” field in the zip Local File Header sections.
       Existing data in the “extra” fields may be altered by this process.

       For more information about how to use zipalign when building your application, please read “Signing  Your
       Application”: https://developer.android.com/tools/publishing/app-signing.html

OPTIONS

       -c     Check alignment only (does not modify file)

       -f     Overwrite existing outfile.zip

       -p     Memory page alignment for stored shared object files

       -v     Verbose output

       -z     Recompress using Zopfli

SEE ALSO

       ZIPTIME(1)

       https://developer.android.com/studio/command-line/zipalign.html

AUTHORS

       The Android Open Source Project.

                                                                                                     ZIPALIGN(1)