NAME

       zipalign - a ZIP/APK alignment tool for Android application files

SYNOPSIS

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

       zipalign [ -f ] [ -v ] <alignment> infile.apk outfile.apk

       To confirm the alignment of existing.apk:

       zipalign -c -v <alignment> existing.apk

       The  <alignment>  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. When using Eclipse with the ADT plugin, the Export
       Wizard will automatically zipalign your .apk after it signs it with your private  key.  The  build
       scripts used when compiling your application with Ant will also zipalign your .apk, as long as you
       have provided the path to your keystore and the key alias in your project ant.properties file,  so
       that the build tools can sign the package first.

       CAUTION:  zipalign  must  only  be performed after the .apk file has been signed with your private
       key. If you perform zipalign before signing, then the signing procedure will undo  the  alignment.
       Also, do not make alterations to the aligned package. Alterations to the archive, such as renaming
       or deleting entries, will potentially disrupt the alignment of the modified entry  and  all  later
       entries. And any files added to an "aligned" archive will not be aligned.

       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

       A summary of options is included below.

       -f     overwrite existing outfile.zip

       -v     verbose output

       -c     confirm the alignment of the given file

AUTHOR

       zipalign was written by the Android Open Source Project.

                                            July 2014                                 ZIPALIGN(1)