Here we report, unveiling the active sites for improved electrocatalytic hydrogen evolution reaction (HER) by structural tailoring of Niobium Disulfide (NbS2). NbS2 synthesized by chemical vapor deposition method, structural deformation is carried out by post-argon plasma and annealing treatment. Plasma-treated (P.T) NbS2 exhibits layer-by-layer stacked (≈250 nm) long and (≈200 nm) wide flakes, which show more edge sites and demonstrates low hydrogen evolution activity. Annealed NbS2 flakes are enlarged in size (≈1 μm) having more surface area which shows additional active basal plane sites and demonstrate remarkable HER performance at 10 mA cm−2. As the thickness of NbS2 is reduced, more basal planes are exposed hence improved HER activity was achieved. This enhanced electrocatalytic change demonstrates that the basal planes are the main active sites for HER in NbS.