Generating Efficient APK by Reducing Size & Improving Performance

Talk delivered in GDG Ahmedabad DevFest 2017 (#DevFestAhm) on 5th November, 2017.

Talked about various tips/tricks and steps to reduce apk size. Also covered some of the tools that I have used for reducing apk size.

Enjoy actual presentation with GIFs http://bit.ly/reduce-apk-size-drive

Transcript

1. Generating Efficient APK
   by Reducing Size & Improving Performance
   

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

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3. When we announced #DevFestAhm
   Source: https://media.giphy.com/media/11sBLVxNs7v6WA/giphy.gif
   

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4. When registration started
   Source:
   

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5. Thank You all for coming for my session
   Source: https://media.giphy.com/media/10Shl99Vghh5aU/giphy.gif
   

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6. @pareshmayani
   

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7. Smart Phones Ecosystem
   

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8. Limited Battery
   

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9. Limited Battery
   Limited Storage
   

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10. Limited Battery
    Limited Storage
    Limited RAM
    

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11. Limited Battery
    Limited Storage
    Limited RAM
    Limited processing power
    

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

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

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14. Why Apk size is important?
    

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

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16. 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
    

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

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

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19. 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
    

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

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

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22. 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
    

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23. 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/
    

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

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25. What goes inside apk
    Let’s Analyse using Apk Analyser
    

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

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27. Assumption
    We all follow at least
    some optimisations
    

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29. Raw File size: Actual size of the apk file
    

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

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

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32. assets: Contains the app's assets like fonts
    

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

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

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

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

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37. AndroidManifest.xml: Contains the core Android manifest file
    

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

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39. 1. Reduce ‘res’ count & size
    

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40. Remove unused resources
    Analyse -> Inspect code...
    

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41. [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
    

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

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43. [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
    

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

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45. [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
    

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46. Reusing resources
    Scenario: ic_arrow_collapse & ic_arrow_expand
    Include only one set of icons
    Create RotateDrawable for another
    
    android:drawable="@drawable/ic_arrow_expand"
    android:fromDegrees="180"
    android:pivotX="50%"
    android:pivotY="50%"
    android:toDegrees="180" />
    

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47. 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);
    

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48. Shape Drawables
    Using XML, you can create simple set of shapes
    Occupies less memory than actual images
    
    
    android:width="5dp"
    android:color="#D8FDFB" />
    android:bottom="7dp"
    android:left="7dp"
    android:right="7dp"
    android:top="7dp" />
    
    
    
    

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50. 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
    

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51. Vector Asset Studio
    

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52. 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
    }
    }
    

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

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54. Optimise PNG images - ImageOptim
    

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

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56. 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
    

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57. 2. Reduce ‘assets’ size
    

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

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59. 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.
    

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60. 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
    

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61. Reduce ‘dex’ count & size
    

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

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63. 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"
    }
    ...
    ...
    }
    }
    

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

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65. 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 (*)
    

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

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67. 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"
    }
    }
    

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68. 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
    

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69. Reduce native ‘libs’ code
    

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

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

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

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73. 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'
    }
    }
    }
    

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74. 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
    }
    }
    }
    

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75. Total Savings ??
    

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76. 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
    

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77. 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
    

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

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79. No Questions!!
    

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

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