In the mol-ecule of the title compound, C(10)H(10)N(4)OS, the configuration about the C=N double bond is E. The dihedral angle between the thia-diazole and benzene rings is 81.1 (1)°. In the crystal, mol-ecules are linked by N-H⋯N and C-H⋯O hydrogen bonds to form a two-dimensional network parallel with the bc plane.