Like any Android library, the Google Play services SDK impacts the final size of applications that include it. Good developers care about the size of their apps, so today we’d like to show you two ways that you can leverage the Android plugin for gradle to reduce the APK size of applications that include Google Play services.

1. Split JAR Architecture

   Beginning with Google Play services 6.5, additional maven artifacts have been added to the Google Repository that contain single domains of functionality. This means that you can include just those portions of Google Play services that your app uses. For example, here’s how to configure gradle to incorporate the JAR that contains functionality relating to ads:

   
   dependencies {
       compile 'com.google.android.gms:play-services-ads:6.5.+'
   }
   

   That line instructs gradle to include everything Mobile Ads developers need, with the exception of the IMA SDK JAR needed for IMA applications.

   Please note that if you currently initialize Mobile Ads SDK banner ads via XML layout files, you should continue including the full Google Play services artifact. See this blog post for more information.

2. Shrink Resources

   The Android gradle plugin supports the ability to automatically exclude unused resources during the build process via the shrinkResources gradle property. To take advantage of this in your release builds, just add “shrinkResources true” to your build.gradle file’s release configuration:

   
   android {
       buildTypes {
           release {
               minifyEnabled true
               shrinkResources true
           }
       }
   }
   

   Note that the shrinkResources property requires that minifyEnabled be set to true as well, though that’s already a good practice for release builds.

Both of these techniques are quick to implement, so consider giving them a try. In testing, the use of shrinkResources and the new, split JAR maven artifacts reduced the APK size of our Interstitial Example by 1.2MB -- almost 50%!

If you have questions about these techniques and how to put them to work in your applications, visit us on the Mobile Ads SDK forum or the IMA SDK forum.

 - Andrew Brogdon, Mobile Ads Developer Relations

Today we’re announcing the release of v6.5 of the Google Mobile Ads SDK! It’s listed as Google Play services 6.5 (Rev. 22) in the Android SDK manager, and is available for download right now. Those of you using Android Studio should download Google Repository (Rev. 14) to get the latest Gradle artifacts.

Under the hood improvements (greater stability, more efficient use of resources) make up most of the changes, but we’re pleased to note that this will be the first version of the SDK to support a split jar architecture. Previously, the SDK was compiled as a single, all-encompassing JAR file. Beginning with this release, however, it’s also built into separate JARs, each covering a specific domain of functionality. Interactive Media Ads (IMA) and Mobile Ads developers can now reference part of the Play Services SDK without needing to import the whole thing. This in turn reduces the APK size and memory footprint of your applications.

Taking advantage of the new architecture is easy -- you just need to change how you’re incorporating the SDK in your build process. Here’s an excerpt from a typical build.gradle file for an app that uses the SDK to display mobile ads:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.google.android.gms:play-services:6.+'
}

And here’s one that targets the ads library specifically, new in v6.5:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.google.android.gms:play-services-ads:6.+'
}

That’s it! Gradle will now incorporate the new, smaller JAR into your application. If your app consumes other services from the SDK, simply add the relevant JARs (play-services-games or play-services-location, for example) to your build file as well.

IMA developers can make this change now. If you’re a Mobile Ads developer, one important thing to note is that the new split jar architecture currently works only with projects that configure banner ads in Java code, and not in XML. We plan to support XML configurations in the future, but for now if you’re defining and configuring your AdViews in an XML layout file, you should continue to reference Play Services in the existing manner.

You can read the Google Play Services Announcement on the Android Developers Blog for a summary of what’s new with this release. For a full list of Mobile Ads SDK changes, check out our release notes. For technical questions, post them on our forum.

 - Andrew Brogdon, Mobile Ads Developer Relations