Android Studio includes an APK Analyzer, that is available in the top menu under:
Build --> Analyze APK...
What is it and how to make the most of it?
After the build process is completed, the APK Analyzer can provide details about the composition of the APK file.
Some benefits of using APK Analyzer:
APK size optimisation: it can show the raw file size (the unzipped size on disk) and the download size (the estimated compressed size). The list of files and folders is sorted by total size in descending order.
View the AndroidManifest.xml file in XML form instead of binary: The manifest file in the APK is usually a binary file. Furthermore, if the project includes more than one manifest file in the APK they will be merged together in a single manifest file. With APK Analyzer it's possible to reconstruct the XML form of the manifest file.
Understand the composition of the .DEX (Dalvik Executable) files: When you click on any DEX file, you will see a summary of how many classes and methods it defines, and how many total references it contains.
Compare APK files: it can be used to show the difference between two different APK files, for example between debug and release builds.
Load ProGuard mappings.
View code and resource entities.
More details are available at this link.
There is also the command-line version of the APK Analyzer.