In the title compound, C8H6N4O2, the tetrazole and benzene rings are planar to within 0.001 (1) and 0.007 (1) A, respectively. These rings are not coplanar in the molecule, the dihedral angle between them being 52.90 (4) degrees. Molecules are connected together by O-H...N and C-H...O hydrogen bonds, forming two-dimensional networks parallel to the xz plane with van der Waals interactions between them.