Density functionals proposed in the literature for describing the behaviour of liquid helium at T = 0 K are examined. In so doing, several properties of the ground states of free films of superfluid ⁴He are calculated by using zero- and finite-range density functional theories and these results are compared to that computed with Monte Carlo simulations. We mainly focus the attention on the energy per particle of the slabs, the surface tension and the width of the liquid-vacuum interfaces, all as a function of the inverse of coverage. The largest differences are found in the case of the surface widths.