In the title compound, C10H10N4O2S2, the tetra-zole and benzene rings are almost normal to one another, with a dihedral angle between their planes of 84.33 (9)°. In the crystal, mol-ecules are linked via pairs of bifurcated O-H⋯(N,N) hydrogen bonds, forming inversion dimers with graph-set motif R 4 (4)(12). The dimers are linked by significant π-π inter-actions involving inversion-related tetra-zole rings and inversion-related benzene rings, with centroid-centroid distances of 3.7376 (14) and 3.8444 (15) Å, respectively.