Porous rocks, foams, cereals, and snow display a diverse set of common compaction patterns, including propagating or stationary bands. Although this commonality across distinct media has been widely noted, the patterns??? origin remains debated???current models employ empirical laws for material-specific processes. Here, using a generic model of inelastic structured porous geometries, we show that the previously observed patterns can be attributed to a universal process of pore collapse. Furthermore, the pattern diversity can be mapped in a phase space of only two dimensionless numbers describing material strength and loading rate.