Running multiple Fortnite accounts on your computer is impossible using the Epic Games Launcher. But not with my special Fortnite Launcher. This tool uses command-line parameters to launch the game using locally stored credentials, saving you the hassle of having to swap between accounts. Additionally, since this tool doesn't make use of the Epic Games Launcher, you don't have to worry about closing it when you exit the game. Plus, it uses way less resources than the Epic Games Launcher, so I call that a win in itself.