In the title compound, C15H15N3O3, the dihedral angle between the triazole ring and coumarin ring system [r.m.s. deviation = 0.040 Å] is 77.40 (6)°. The O atom of the hydroxymethyl group deviates from the triazole ring plane by 1.345 (1) Å. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds generate R22(22) loops; C—H...O and C—H...N interactions link the dimers into a three-dimensional network.