Organic–inorganic halide perovskite have shown great promise for photovoltaic applications due to their unprecedented optoelectronic properties and low manufacturing cost. However, the commercialization of this emerging technology is hampered by its thermal instability and intrinsic Pb-toxicity. Here, we report first-principles investigations on stability and optoelectronic properties of a series of all-inorganic lead-free metal halide perovskite-like materials AMX₄ (A = Cs, Ag, and Rb; M = In, Sb, and Bi; X = Cl, Br, and I). Our calculations show that AgSbI₄ and AgBiI₄ have direct bandgaps of 1.63 and 1.44 eV, which possess strong interband optical absorption (≈10⁵ cm⁻¹). Based on these favorable properties, we also simulated the AgSbI₄- and AgBiI₄-based thin film solar cells with the SCAPS-1D code and achieve high PCE of 24.19% and 26.70%, respectively. These results reveal that the AMX₄ perovskite-like materials could serve as potential alternatives to Pb-based halide perovskites in photovoltaic devices.