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)