As number of apps in the App Stores mushrooming rapidly, there are two looming challenges that constantly annoy users. One, the space consumption of mobile apps and two, the overall storage space of phones. It seems that more focus is given to adding new features on Phones than some worthy solution for the storage concerns.

In this blog we’ll look into different ways an iPhone app size can be reduced. There are two factors that we need consider before we move ahead. Firstly, we need to understand that storage issues are inevitable, and bound to happen sooner or later due to very limited storage capacities in phones. Secondly, many of us don’t know is that the storage issues can be tackled right from the early stages of mobile app development.

You may be a mobile app developer or an app owner, and if you wish to overcome this shortcoming, the following methods can help you deliver a lighter app for your users.


Understanding the space demands


Just like computers, iPhones cannot function without the Operating System. And it goes without saying that a dedicated amount of space is already taken by the phone’s OS before you accommodate your favorites apps in it. For example, if your iPhone has 6GB internal space, roughly about 4GB is dedicated to the OS. The remaining is all you’ve got for your apps. And this remaining space, too, over a course of time, shrinks as apps needs to update itself constantly. To say the least, your space constraint is imminent.

So, how can you workaround this problem?


Welcome to App Thinning


The process of App Thinning is not new. According to Apple’s Distribution Guide, App Thinning means:

“The store and operating system optimize the installation of iOS (in this case), tvOS, and watchOS apps by tailoring app delivery to the capabilities of the user’s particular device, with minimal footprint. This optimization, called APP THINNING, lets you create apps that use the most device features, occupy minimum disk space, and accommodate future updates that can be applied by Apple.”

To put it in a different way:

App Thinning is the process employed by iOS app developers to decrease the size of the app on the users’ devices. The apps are created in such a fashion that they utilize most device features, yet consume minimum disk space. This way users can use these apps for longer time without having to worry about the bothersome ‘Disk Almost Full’ pop-up messages, or eventually the apps stops updating itself altogether.


Ways you could ‘thin out’ the app


As mentioned earlier, there are different ways developers can reduce an iOS app’s size, and better optimize it for the end users.

1. Slicing

2. Bitcode

3. On-demand Resources (ODR)


1. Slicing

iOS app development has evolved a lot in the recent times. Today, universal apps are widely being used. These apps can be installed on all iPhones as well as on iPads. A single app can be installed on both, smartphones and tablets.

Now, smartphones and tablets vary in size, functionalities and other capabilities. When the app is being developed, developers make sure that it contains relevant visual and other assets required to work on both devices. When you download an universal app, all the assets are downloaded as well, making the app size bigger. The downside is that, for example, if you are using the app in your iPhone 6 it has all the assets to work on other models and tablets as well, but they are not utilized. These assets are put into use only when you install the app in other iPhone models or iPads. Otherwise, they remain unused, taking needless space of your phone.

The Slicing method is specifically designed to combat this redundancy. Through Slicing app developers can enable an app to only download a specific set of assets required to run on a particular device. If an user downloads the app in a different device, instead of downloading all assets, it will only download a relevant pack of assets required to run on that device.

This way the app does not take more space than what is needed, which also makes the application lighter.


2. Bitcode

This concept is somewhat similar to the Slicing method, but takes a different approach. Typically, once the app is developed, the developer uploads a compiled binary file onto the iTunes Connect (Apple’s platform for uploading and managing iOS apps and other content). Then, Apple will check the apps and then make it available to users on its App Store.

With bitcode, developers are no longer required to upload a singular binary file, instead an intermediate representation of the compiled file is uploaded. This will be compiled on-demand every time a user installs a program. The compilation takes place when Apple identifies the device the app is being installed; then it picks the right relevant assets for that particular device, and then compiles them into a file for the user to download and install.

This method is widely carried out along with the other two methods to keep an app’s size as minimal as possible.


3. On-demand Resources (ODR)

Today’s apps pack a lot of interesting and unique features to entice its users. The more complex the features are, the more assets and information it needs to let the users experience those amazing features and the full potential of the app. However, as it appears, many users do not use all those features of the app, which means the app is consuming spaces for the features the users are not using. Gaming apps are a good example.

On-demand Resources are the ones whose app contents are hosted separately from the app bundle, which can be downloaded from the App Store as and when needed. Here, the app developer tags every resource while building the app. Also, these resources are designed to run in the background in a transparent manner, showing up only when users require the said features – hence the name, On-demand Resources (ODR).



As mentioned earlier, the app thinning method is not new and several top companies have implemented these methods to reduce their app size. In our current application and smartphone world, space – the empty void in our devices – still remains as an essential and valuable component, where we all are forced to be as frugal as possible. In the future we might have a unlimited space at our disposals. But as of now, these methods are our only saving grace.




At Ideaplunge, we make it a point to provide forward-thinking software solutions to drive ideas from conception to completion. Using the most up-to-date tech solutions and world standard methodologies, we help our clients reach their goal, effortlessly. We specialize in the Android App development, iOS app development, Salesforce development, UI/UX designing, Dashboards, and Web solutions. We are one of the sought-after app development companies in Bangalore with clients from seven different countries.

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