In the mol-ecule of the title compound, C(10)H(10)N(2)O(2), the rings are nearly coplanar, making a dihedral angle of 2.35 (5)°. In the crystal structure, inter-molecular C-H⋯O, C-H⋯N and O-H⋯O hydrogen bonds link the mol-ecules, generating R(4) (4)(22) and R(4) (4)(24) ring motifs to form a three-dimensional network. A weak π-π inter-action between the pyridazinone and benzene rings further stabilizes the crystal structure, with a centroid-centroid distance of 3.709 (3) Å and an inter-planar separation of 3.312 Å.