To provide a dye excellent in especially moisture resistance, and bronze resistance, light resistance, (ozone)gas resistance and storage stability in a solution, having high print density and low chroma, having high quality black color tone with low color rendering property when recorded on a paper exclusively used for inkjet, to provide an ink composition containing the dye, especially an ink composition for inkjet recording.

There is provided an azo compound represented by the formula (1), or a tautomer thereof or their salts. In the formula (1), X represents a phenyl group may have a substituent, R¹ to R⁴ represent each independently a hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a sulfo group, a sulfamoyl group, a (C1 to C4) alkyl group, a (C1 to C4) alkoxy group and the like, and n represents an integer of 0 or 1).