Do I need to delete an app's related data in ~/Library myself when I delete it?

Question

When I delete an app (move it to Trash) do I also need to delete its related data in ~/Library myself?

According to this:

• Does deleting Mac App Store apps in Launchpad delete related files in the Library folders too?

some apps keep their data in ~/Library even after it's deleted. I find it kind of annoying that the app keeps its data even after it is deleted. The only reason I can think of that usage is maybe if I reinstall the app later, I can get my old data back. But I still prefer to deleting all its related data if I delete the app.

My second question is is this the main function of other uninstaller tools?

Answer 1

When I delete an app (move it to Trash) do I also need to delete its related data in ~/Library myself?

A user is not generally expected to delete those file themselves. If you are aware of, and wish to delete them, you can do so. The most that you would lose is the app specific preferences and any user data which could be re-used if you reinstall the app in future.

My second question is is this the main function of other uninstaller tools?

Since you didn't name any tool, this cannot be answered concretely, and would depend upon choice of tool. But a tool that lets you delete an apps' related data is generally expected to show the files/folders that it would affect and should let you choose what items to keep.

Answer 2

You can delete the application data if you wish. If you leave it, and you later install the application again, things like preferences will be restored from the original installation.

Regarding your second question about uninstallers, most applications don't need them or provide them. They're usually only provided for applications that make configuration changes to your account or system. For instance, if an application automatically runs in the background when the system boots, the uninstaller will remove that setting.

The uninstaller might remove files in ~/Library, but I think that tends to be more in the province of third party application cleaners. These try to find all the files related to the application and remove them.