Fly ash-GGBS (ground-granulated blast furnace slag)-based self-compacting geopolymer concrete (SCGC) is a sustainable and eco-friendly alternative to cement-based concrete, particularly for precast construction. This study examines the use of fly ash and GGBS as major binders in self-compacting geopolymer concrete without Portland cement. Alkaline activators, usually sodium hydroxide and sodium silicate, start geopolymerization. The research optimizes mix proportions for self-compacting concrete flowability, segregation resistance, mechanical qualities, and durability. A tested the fresh characteristics of SCGC using slump flow, T50, V-funnel, and L-box methods. It also assessed strengths such as compressive, tensile, and flexural. GGBS accelerates strength development, making it suited for precast applications that need quick demolding and handling. The study shows that using industrial by-products like fly ash and GGBS minimizes the carbon footprint, energy utilization, and dependency on natural resources in this concrete. This SCGC satisfies precast construction performance criteria and worldwide environmental objectives, providing a construction industry solution. They found that fly ash-GGBS-based SCGC has excellent fresh and hardened characteristics and long-term durability for large-scale precast construction. The compressive strength of M50-grade geopolymer concrete containing 80% fly ash and 20% GGBS is 37 MPa after 7 days. It reaches 43 MPa after 14 days and 58 MPa after 28 Mpa.