What is “size information”?

“Size information” contains size data for Dart code,
native code, and non-code elements of your app,
like the application package, assets and fonts. A “size
information” file contains data for the total picture
of your application size.

Dart size information

The Dart AOT compiler performs tree-shaking on your code
when compiling your application (profile or release mode
only—the AOT compiler is not used for debug builds,
which are JIT compiled). This means that the compiler
attempts to optimize your app’s size by removing
pieces of code that are unused or unreachable.

After the compiler optimizes your code as much as it can,
the end result can be summarized as the collection of packages,
libraries, classes, and functions that exist in the binary output,
along with their size in bytes. This is the Dart portion of
“size information” we can analyze in the app size tool to further
optimize Dart code and track down size issues.