In the indane ring system of the title mol-ecule, C(13)H(12)O(4), the hy-droxy-bearing C atom is 0.134 (1) Å out of the plane of the remaining essentially planar atoms (r.m.s. deviation = 0.010 Å). In the crystal, mol-ecules are linked into chains along the b axis by inter-molecular O-H⋯O hydrogen bonds. Additional stabilization is provided by weak inter-molecular C-H⋯O hydrogen bonds.