Code Optimization with ProGuard and R8 in Android
Article Summary
Enes İğneci from Teknasyon Engineering breaks down why your Android app might be bloated, slow, and vulnerable. The fix? Two powerful code optimization tools most developers underutilize.
This technical guide explores ProGuard and R8, Android's code shrinking and obfuscation tools. Enes walks through how these tools reduce app size, protect against reverse engineering, and improve runtime performance, with R8 emerging as the faster, smarter successor to ProGuard.
Key Takeaways
- R8 integrates with D8 compiler for faster builds and smarter code removal
- Includes 15+ production ready ProGuard rules for Kotlin, Compose, and Retrofit
- Mapping files decode obfuscated crash logs in Firebase Crashlytics
- Vertical and horizontal class merging strategies optimize resource usage
- DexGuard adds encryption and tamper detection for commercial apps
R8 delivers smaller APKs, faster builds, and better security with less manual configuration than ProGuard, making it the clear choice for modern Android development.
About This Article
Android apps often carry unused dependencies and redundant methods that make APK files larger and create security risks through reverse engineering. Cleaning up the code systematically helps address this.
Enes İğneci shows how R8's D8 compiler combines shrinking, desugaring, and optimization in a single build step. This eliminates the multiple stages that older ProGuard workflows required.
R8 produces faster builds and smaller app packages by using method inlining and class merging, both vertical and horizontal. It also requires less manual rule configuration than ProGuard.
