Generating Efficient APK by Reducing Size & Improving Performance

Slides Slides: ● Presentation with GIFs: http://bit.ly/reduce-apk-size-drive ● Speakerdeck: http://bit.ly/reduce-apk-size

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@pareshmayani

Smart Phones Ecosystem

Limited Battery

Limited Battery Limited Storage

Limited Battery Limited Storage Limited RAM

Limited Battery Limited Storage Limited RAM Limited processing power

Limited Battery Limited Storage Limited RAM Limited processing power Limited Data/Network Connectivity

Limited Battery Limited Storage Limited RAM Limited processing power Limited Data/Network Connectivity Billion Users

Why Apk size is important?

Those big and bloated apk... Source: https://media.giphy.com

And when you can’t use such big apk That moment when apk is crashing Waste of user’s time Waste of user’s data pack Source: https://media.giphy.com

Because everyone doesn’t have OnePlus Source: https://media.giphy.com/media/l0MYQgkYlybdCYD3a/giphy.gif

Why apk size is important? 1. Internet connectivity 2. Device specifications 3. Billion Users: To get your next billion users

1. Internet Connectivity Limited internet connectivity (In growing countries like India) Limited data pack/plan Costly data plan (Each bytes affects user’s wallet) Large app size causes longer time to download All users don’t have good internet bandwidth/connectivity

The Average Internet Speed In India: Steady Progress Source: https://dazeinfo.com/2017/06/02/india-internet-speed-growth-q1-2017/

Good news: 4G is getting rolled out in India Source: https://media.giphy.com

2. Device specifications Device specification includes: Storage , Battery, RAM, Processing Power Low/Mid range devices have 8GB/16GB storage Low/Mid range devices have 1GB/2GB RAM Lesser the storage your app uses, user can enjoy more apps and can store more pictures/videos All users don’t have higher specification devices

Google IO 2017 - Points > 100M users came online in 2016 1B 2G devices expected in 2020 50% of India is on 2G 33% users run out of storage in India every day Data is expensive – it costs ~$2 to download a 40MB free app in India Source: Google IO 2017 & https://ashishb.net/tech/google-io-2017-android-notes/

Apk size has an impact on How fast your app loads How much memory it uses How much power it consumes

What goes inside apk Let’s Analyse using Apk Analyser

Case Study Let’s take my any project P.S. It’s already partially optimised

Assumption We all follow at least some optimisations

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Raw File size: Actual size of the apk file

Download size: Estimated size of file for the new installations (Google play store server highly optimised file)

res: contains all the resources files like images, menus, layouts, etc. (those resources which aren’t compiled into resources.arsc)

assets: Contains the app's assets like fonts

classes.dex: dex file which contains all the byte code files of your java code that will run on Dalvik/ART virtual machine

lib: Contains the compiled code that is specific to the software layer of a processor.

resources.arsc: Contains compiled resources. Contains the XML content from all configurations of the res/values/ folder.

META-INF: Contains the CERT.SF and CERT.RSA signature files, as well as the MANIFEST.MF manifest file

AndroidManifest.xml: Contains the core Android manifest file

Files to concentrate on res + assets + classes.dex + lib + resources.arsc = 98.7%

1. Reduce ‘res’ count & size

Remove unused resources Analyse -> Inspect code...

[Result] Remove unused resources `res` Reduction => 54.9% to 48.1% = Total 6.8% reduction Raw File Size => 24.1 MB to 21.9 MB = -2.2 MB Download Size => 21.8 MB to 19.7 MB = -2.1 MB

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

[Result] Shrinking resources `res` Reduction => 48.1% to 46.3% = Total 1.8% reduction Raw File Size => 21.9 MB to 21.2 MB = -0.7 MB Download Size => 19.7 MB to 19 MB = -0.7 MB

Exclude Sparse Translation android { defaultConfig { resConfigs "en", "fr" } }

[Result] Exclude Sparse Translation Raw File Size => 21.2 MB to 20.5 MB = -0.7 MB Download Size => 19 MB to 18.9 MB = -0.1 MB

Reusing resources Scenario: ic_arrow_collapse & ic_arrow_expand Include only one set of icons Create RotateDrawable for another

Reusing resources - setColorFilter Include only one set of icons Apply color filter PorterDuff.Mode mMode = PorterDuff.Mode.SRC_ATOP; Drawable d = getResources().getDrawable(R.drawable.ic_tier_pressure_fluid); d.setColorFilter(ContextCompat.getColor(this, R.color.colorAccent),mMode);

Shape Drawables Using XML, you can create simple set of shapes Occupies less memory than actual images

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Vector Drawables Based on Vector Graphics Scaled without loss of display quality, means same file is resized for different screen densities without loss of image quality VectorDrawable & VectorDrawableCompat AnimatedVectorDrawable & AnimatedVectorDrawableCompat

Vector Asset Studio

Crunch PNG files aapt tool can optimize the image resources placed in res/drawable/ with lossless compression can convert a true color PNG that does not require more than 256 colors to an 8-bit PNG with a color palette. With Android plugin for Gradle 3.0.0 , AAPT2 is now enabled by default. android { aaptOptions { cruncherEnabled true } }

Optimise PNG images Command Utility tools PngCrush, pngquant for Lossy compression Pngquant has a GUI tool - ImageOptim for Mac

Optimise PNG images - ImageOptim

Optimise video files HD Quality videos are not required for mobile apps Compress it using tools available over web

Step 1 - Result Raw File Size => 24.1 MB to 17.3 MB = -6.8 MB Download Size => 21.8 MB to 15.7 MB = -6.1 MB

2. Reduce ‘assets’ size

Use downloadable fonts Remove font files from ‘assets’ folder Use downloadable fonts

How does Downloadable font works A font provider is an application that retrieves fonts and caches them locally so other apps can request and share fonts.

Step 2 - Result Raw File Size => 17.3 MB to 14.6 MB = -2.7 MB Download Size => 15.7 MB to 13 MB = -2.7 MB

Reduce ‘dex’ count & size

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

Proguard buildTypes { release { minifyEnabled true shrinkResources true proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' proguardFile "$project.rootDir/settings/proguard_files/proguard-square-okhttp3.pro" proguardFile "$project.rootDir/settings/proguard_files/proguard-google-play-services.pro" proguardFile "$project.rootDir/settings/proguard_files/proguard-okio.pro" proguardFile "$project.rootDir/settings/proguard_files/proguard-crashlytics.pro" proguardFile "$project.rootDir/settings/proguard_files/proguard-gson.pro" } ... ... } }

Analyze and maintain dependencies You never know which sdk/libraries includes what dependencies ./gradlew app:dependencies

Analyse dependencies +--- com.android.support:design:26.1.0 | +--- com.android.support:support-v4:26.1.0 | | +--- com.android.support:support-compat:26.1.0 | | | +--- com.android.support:support-annotations:26.1.0 | | | \--- android.arch.lifecycle:runtime:1.0.0 | | | +--- android.arch.lifecycle:common:1.0.0 | | | | \--- com.android.support:support-annotations:26.1.0 | | | +--- android.arch.core:common:1.0.0 | | | | \--- com.android.support:support-annotations:26.1.0 | | | \--- com.android.support:support-annotations:26.1.0 | | +--- com.android.support:support-media-compat:26.1.0 | | | +--- com.android.support:support-annotations:26.1.0 | | | \--- com.android.support:support-compat:26.1.0 (*) | | +--- com.android.support:support-core-utils:26.1.0 | | | +--- com.android.support:support-annotations:26.1.0 | | | \--- com.android.support:support-compat:26.1.0 (*) | | +--- com.android.support:support-core-ui:26.1.0 | | | +--- com.android.support:support-annotations:26.1.0 | | | \--- com.android.support:support-compat:26.1.0 (*) | | \--- com.android.support:support-fragment:26.1.0 | | +--- com.android.support:support-compat:26.1.0 (*) | | +--- com.android.support:support-core-ui:26.1.0 (*) | | \--- com.android.support:support-core-utils:26.1.0 (*)

Analyze and maintain dependencies Exclude repetitive dependencies Benefits: ● Can avoid version conflicts ● Can avoid multiple copy of same sdk

Analyze and maintain dependencies dependencies { ... ... compile('co.adcel.android:adcel:1.2.1') { exclude group: "com.google.android.gms" // exclude group: "com.startapp.android" // exclude group: "com.personagraph" exclude group: "com.flurry" exclude group: "com.android.support" } compile ("jp.wasabeef:recyclerview-animators:2.2.6") { exclude group: "com.android.support" } }

Google play services Include only required sub-sdks from Google play service compile 'com.google.android.gms:play-services-gcm:' + rootProject.ext.PLAY_SERVICE_LIB_VERSION compile 'com.google.android.gms:play-services-location:' + rootProject.ext.PLAY_SERVICE_LIB_VERSION compile 'com.google.android.gms:play-services-maps:' + rootProject.ext.PLAY_SERVICE_LIB_VERSION compile 'com.google.android.gms:play-services-places:' + rootProject.ext.PLAY_SERVICE_LIB_VERSION compile 'com.google.android.gms:play-services-ads:' + rootProject.ext.PLAY_SERVICE_LIB_VERSION

Reduce native ‘libs’ code

Remove deprecated httpclient jars Remove legacy jars ● Httpclient-4.5.2.jar ● Httpcore-4.4.4.jar useLibrary 'org.apache.http.legacy'

[Result] Remove deprecated httpclient jars Raw File Size => 14.6 MB to 14.5 MB = -0.1 MB

Splitting apks Configure multiple apks for different densities Configure multiple apks for different CPU architecture (ABI)

Configure multiple apks for densities android { ... splits { // Configures multiple APKs based on screen density. density { // Configures multiple APKs based on screen density. enable true // Specifies a list of screen densities Gradle should not create multiple APKs for. exclude "ldpi", "xxhdpi", "xxxhdpi" // Specifies a list of compatible screen size settings for the manifest. compatibleScreens 'small', 'normal', 'large', 'xlarge' } } }

Configure multiple apks for ABIs android { ... splits { // Configures multiple APKs based on ABI. abi { // Enables building multiple APKs per ABI. enable true // By default all ABIs are included, so use reset() and include to specify that we only // want APKs for x86, armeabi-v7a, and mips. // Resets the list of ABIs that Gradle should create APKs for to none. reset() // Specifies a list of ABIs that Gradle should create APKs for. include "x86", "armeabi-v7a", "mips" // Specifies that we do not want to also generate a universal APK that includes all ABIs. universalApk false } } }

Total Savings ??

Total Savings Raw File Size => 24.1 MB to 14.5 MB = -9.4 MB Download Size => 21.8 MB to 13 MB = -8.8 MB Notes: ● Splitting is not applied yet ● This was already partially optimised, as all devs used to follow at least some optimisations

Remember Lesser is always better Less number of files = low maintenance time Less number of files = reduced apk size = faster loading time Lesser the apk size = faster the download time Less number of files = faster building time

+PareshMayani @pareshmayani Technical Lead - Android @ Simform Manager, GDG Ahmedabad

No Questions!!

Thank You! Paresh Mayani @pareshmayani Slides: ● Presentation with GIFs: http://bit.ly/reduce-apk-size-drive ● Speakerdeck: http://bit.ly/reduce-apk-size