The physical properties of the isomers of xylene differ slightly. The melting point ranges from  (m-xylene) to  (p-xylene)—as usual, the para isomer's melting point is much higher because it packs more readily in the crystal structure. The boiling point for each isomer is around . The density of each isomer is around  and thus is less dense than water. The odor of xylene is detectable at concentrations as low as 0.08 to 3.7 ppm (parts of xylene per million parts of air) and can be tasted in water at 0.53 to 1.8 ppm.
Xylenes form azeotropes with water and a variety of alcohols. The azeotrope with water consists of 60% xylenes and boils at 94.5 °C. As with many alkylbenzene compounds, xylenes form complexes with various halocarbons. The complexes of different isomers often have dramatically different properties from each other.