The title compound, C(8)H(10)O(3), is close to planar (r.m.s. deviation = 0.042 Å) apart from the hydroxyl O atom [deviation = 1.285 (1) Å] and an intra-molecular O-H⋯O hydrogen bond occurs. In the crystal, inter-molecular O-H⋯O links lead to chains propagating in [001].