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 provides 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)