Short range order and topology of GexS100-x glasses over a broad composition range (20 ≤ x ≤ 42 in at%) was investigated by neutron diffraction, X-ray diffraction, and Ge K-edge extended X-ray absorption fine structure (EXAFS) measurements. The experimental data sets were fitted simultaneously in the framework of the reverse Monte Carlo simulation method. It was found that both constituents (Ge and S) satisfy the Mott-rule in all investigated glasses: Ge and S atoms have 4 and 2 neighbours, respectively. The structure of these glasses can be described with the chemically ordered network model: Ge-S bonds are preferred; S-S bonds are present only in S-rich glasses. Dedicated simulations showed that Ge-Ge bonds are necessary in Ge-rich glasses. Connections between Ge atoms (such as edge-sharing GeS4/2 tetrahedra) in stoichiometric and S-rich glasses were analysed. The frequency of primitive rings was also calculated. •Ge atoms have 4, S atoms 2 nearest neighbor in all compositions investigated.•Chemically ordered network model is consistent with the experimental data.•Ge-Ge bonds are present in Ge-rich Ge42S58 glass.•Alternating 4 and 6 membered Ge-S rings are preferred in S-rich glasses.•membered rings are the most frequent in stoichiometric Ge33S67 glass.