Portland cement is one of the primary components of concrete. However, around 5-30% of the carbon dioxide emissions in the globe are produced by the manufacture of cement. Therefore, Engineers and scientists must produce and utilize green construction materials to achieve a more sustainable environment by developing geopolymer concrete (GPC). This study investigates the strength characteristics of sustainable GPC using binders such as ground granulated blast furnace slag (GGBFS) and fly ash (FA) (50:50), natural fine aggregate with granulated blast furnace slag (GBFS) (replaced by 0%, 25%, 50%, 75%, 100%) and natural coarse aggregate, respectively. The flexural strength, split tensile strength, and compressive strength are found to be better in the case of 50:50 substitution of NFA to GBFS. This enhancement of strength is found due to GBFS acts as an inner filling material. Moreover, GBFS has pozzolanic behavior that leads to the increment in strength. Hence, geopolymer concrete with GBFS may replace regular Portland cement for sustainable green concrete production in future.