Building a mobile application involves dozens of small tasks beyond writing code.
Authentication, navigation, APIs, notifications, permissions, and testing usually get most of our attention.
Then, as the application gets closer to release, we remember something else.
We need the app icons.
Not just one icon, either.
Android and iOS have different requirements, and preparing the necessary image files can become surprisingly repetitive.
Let's look at how app icons work and how to simplify the process.
Why can't we just use one PNG?
Imagine you've designed a beautiful 1024 × 1024 pixel logo for your application.
It looks great.
So why can't you just add that PNG to your project and let the operating system handle everything?
Technically, platforms and development tools can resize images. But mobile application projects typically expect assets organized according to platform-specific conventions.
Android supports different screen densities and uses resources such as mipmap-mdpi, mipmap-hdpi, and others.
iOS projects commonly use an asset catalog containing an AppIcon image set.
Providing appropriately sized assets helps ensure that your application icon looks consistent across supported devices.
It also makes the project easier to manage.
Understanding Android icon sizes
Android traditionally organizes launcher icon resources by screen density.
A common set of launcher icon sizes looks like this:
| Density | Icon size |
|---|---|
| mdpi | 48 × 48 |
| hdpi | 72 × 72 |
| xhdpi | 96 × 96 |
| xxhdpi | 144 × 144 |
| xxxhdpi | 192 × 192 |
A typical Android resource directory might look like:
app/src/main/res/
├── mipmap-mdpi/
│ └── ic_launcher.png
├── mipmap-hdpi/
│ └── ic_launcher.png
├── mipmap-xhdpi/
│ └── ic_launcher.png
├── mipmap-xxhdpi/
│ └── ic_launcher.png
└── mipmap-xxxhdpi/
└── ic_launcher.png
In the Android manifest, the application may reference the icon like this:
<application
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name">
</application>
Of course, modern Android applications also commonly use adaptive icons.
Adaptive icons have separate foreground and background layers, allowing Android launchers to apply different masks and shapes.
A simple collection of PNG files doesn't automatically replace a correctly configured adaptive icon.
For modern Android applications, developers should review adaptive icon requirements as well.
What about iOS?
Apple uses its own asset catalog system.
In an Xcode project, you'll commonly encounter a directory named:
AppIcon.appiconset
This contains icon assets and a Contents.json file describing how those assets correspond to the relevant icon slots.
Rather than manually referencing each icon in code, Xcode uses the asset catalog configuration.
For App Store distribution, a 1024 × 1024 pixel icon is important.
One detail to remember: the App Store icon should not contain transparency. If you're starting with a transparent logo, prepare a version with an appropriate opaque background.
The platform handles the final icon presentation, including corner treatment.
Preparing a good source image
Before generating all the required sizes, focus on the original design.
Ideally, start with a high-resolution square image.
For example, 1024 × 1024 pixels is a useful starting point.
Here are a few practical design considerations.
Keep it simple. A detailed illustration may look great at full resolution but become difficult to recognize on a home screen.
Leave some breathing room. Avoid placing important visual elements too close to the edges, where platform-specific masking may affect them.
Think about contrast. The icon should remain recognizable against a variety of wallpapers and interface themes.
Test at small sizes. Don't make design decisions using only the large original image.
These considerations matter more than squeezing extra visual detail into the icon.
Generating the files without repetitive resizing
You can prepare all these assets using design software or platform-specific development tools.
Android Studio, for example, includes Image Asset Studio for creating icons.
But when you're working across multiple projects, a straightforward icon generator can save manual work.
One option is the ImgTask App Icon Pack Generator.
You upload a square logo, and it creates a downloadable ZIP containing Android launcher PNG sizes and an iOS AppIcon.appiconset directory.
The generated package includes Android mipmap folders, a Play Store icon, and iOS icon assets with a Contents.json file.
Image processing happens locally in the browser.
For a standard raster icon workflow, this can reduce the time spent preparing repetitive asset sizes.
You should still review the exported assets and make any platform-specific adjustments required by your application.
A simple release checklist
Before publishing your mobile application, check that:
- Your source logo is high resolution.
- The Android launcher icon looks sharp at different densities.
- Adaptive icons are configured if required.
- The iOS asset catalog contains the expected icon sizes.
- The App Store icon satisfies Apple's current requirements.
- The icon remains recognizable at small sizes.
- You've tested the icon on actual devices or emulators.
Also make sure your application's icon visually matches its store listing and brand identity.
Consistency matters.
Final thoughts
Generating mobile app icons isn't particularly complicated, but it can be a repetitive part of the development process.
Once you've built a few mobile applications, you start appreciating small workflow improvements.
Whether you use Android Studio, Xcode, a design tool, or an online generator, the underlying goal is the same.
Start with a good source image, prepare the assets correctly, and test the final icon where users will actually see it.
A great app deserves an icon that feels just as polished.
How do you handle app icon generation in your projects? Do you use platform-specific tools or generate the assets separately?
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