How to Compress PNG Files for Android and iOS App Development
By admin · Jun 4, 2026
In mobile app development, PNG files make up a significant portion of your app bundle size. Icons, splash screens, UI elements, illustrations, and onboarding images all contribute to your APK or IPA size — and large apps have lower install conversion rates, higher uninstall rates, and worse performance on low-end devices.
Why PNG Size Matters in Mobile Apps
- Google Play recommends app size under 80 MB for best install rates
- Apple App Store has a 200 MB cellular download limit (OTA updates)
- Users abandon app downloads that take more than 30 seconds
- Large apps get uninstalled first when users run out of storage
- In-app loading of PNG assets affects rendering speed and memory usage
Types of App PNG Assets and Target Sizes
| Asset Type | Typical Sizes Needed | Target File Size |
|---|---|---|
| App icon (iOS) | 20px to 1024px (multiple sizes) | Under 100 KB total for all sizes |
| App icon (Android) | 36px to 192px (mdpi to xxxhdpi) | Under 50 KB total |
| Splash screen | 1×, 2×, 3× for iOS; various for Android | Under 200 KB per asset |
| UI icons (per icon) | 2×, 3× for iOS; mdpi to xxxhdpi | Under 10 KB per icon |
| Illustration / onboarding | 1×, 2×, 3× | Under 150 KB per image |
| Background images | Screen resolution variants | Under 300 KB |
iOS PNG Compression Workflow
Asset Catalog Compression (Xcode)
iOS stores PNG assets in .xcassets folders. Xcode automatically runs pngcrush on PNGs during build — but pre-compressing with pngquant achieves much greater savings.
Step-by-Step for iOS
- Export PNG assets from your design tool (Sketch, Figma, Adobe XD)
- Compress with compresspngfile.com (batch upload all sizes at once)
- Add compressed PNGs to your .xcassets in Xcode
- Xcode's pngcrush runs on already-compressed files — minimal additional compression
- Result: app bundle significantly smaller than uncompressed PNGs
Android PNG Compression Workflow
Android Resource Folders
Android uses density-specific resource folders: drawable-mdpi, drawable-hdpi, drawable-xhdpi, drawable-xxhdpi, drawable-xxxhdpi.
Step-by-Step for Android
- Export PNG assets at 4× (xxxhdpi) from your design tool
- Scale down to create mdpi, hdpi, xhdpi, xxhdpi versions
- Batch compress all density variants with compresspngfile.com
- Place compressed PNGs in appropriate drawable folders
- Build APK — significantly smaller bundle size
Using pngquant in Your Build Pipeline
For automated compression in your CI/CD pipeline:
# Android: compress all drawable PNGs before build
find app/src/main/res -name "*.png" -exec pngquant --quality=65-80 --ext .png --force {} \;
# iOS: compress all asset catalog PNGs before build
find . -path "*.xcassets/*.png" -exec pngquant --quality=65-80 --ext .png --force {} \;Real App Size Reduction Results
| App Type | Before PNG Compression | After PNG Compression | Savings |
|---|---|---|---|
| Simple utility app (50 PNG assets) | 12 MB | 3.2 MB | 73% |
| Social media app (200 PNG assets) | 45 MB | 10 MB | 78% |
| Game with sprite sheets (500 PNG assets) | 120 MB | 26 MB | 78% |
| E-commerce app (100 PNG assets) | 28 MB | 6 MB | 79% |
Vector vs PNG: When to Use Each
Where possible, use vector formats (SVG on web, PDF/SVG on iOS, VectorDrawable on Android) for UI icons — they scale perfectly and have tiny file sizes. Use PNG for:
- Complex illustrations that can't be vectorized
- Photos (though JPG is usually better)
- Assets that look poor when vectorized
- Transparency-dependent graphics where SVG has rendering issues
Conclusion
PNG compression is one of the easiest ways to significantly reduce your app bundle size. For the design-to-development handoff, use compresspngfile.com to compress all PNG assets before adding them to your Xcode or Android Studio project. For automated CI/CD compression, integrate pngquant into your build scripts.