How to find unused flutter classes in Android Studio or Visual Studio Code

I'm not sure about unused classes per se. I know you can clean up unused imported files at least.

In Android Studio there is an Optimize Imports function that you can call on a particular file. It removes any unused imports. It appears you can also configure the setting on on commits in the settings. Check out Version Control -> Commit Dialog for Optimize Imports.

In VSCode's Problems tab, you can see unused variables, I'm not 100% sure it applies to classes though. But your editor may also notify you via its syntax highlighting of a class that is unused as well.

Unused classes in the project are usually searched by the option Global unused analysis, as mentioned in one of the previous answers on this topic https://stackoverflow.com/a/38244028/10498374

I think the dart files are not supported yet.

A temporary solution, you can delete the file that you do not want and if it is used within the project, Android Studio will tell you that it is used

In VS code all unused classes in a file are marked grey or underlined, and when you hover on them a popup will appear telling you that the class has not been used anywhere within your the current file. you can then delete all of such classes.

alternatively, for each class you suspect is unused, you can make a global search, by pressing on the loop icon on the top left side of vs and input the name of the class as your search key, from there you can see if it is used or not