The zwitterionic title compound, C(13)H(8)F(2)N(4)S, is situated on a twofold rotation axis running along the C-S [1.691 (2) Å] single bond. The phenyl-ene ring is twisted out of the tetra-zolium plane by 42.18 (7)°. Relatively short distances [3.7572 (9) and 4.0625 (6) Å] between the centroids of the phenyl-ene and tetra-zolium rings of neighbouring mol-ecules suggest π-π inter-actions. The crystal under investigation was a non-merohedral twin, with a 33% twin component.