Depends on the program, they don't use system libraries so if they have a lot of dependencies then they'll be larger. An example: Steam Flatpak: 35MB Steam pacman: 19MB On one hand, it's only a few MB. On the other hand, it's 54% larger. Flatpaks can also depend on other flatpaks. For example, graphics card support requires about 1-1.5GB of flatpak dependencies even though your system already has graphics card drivers.