This review discusses the recent advancements in gel polymer electrolytes (GPEs) for flexible energy storage applications, focusing on batteries and supercapacitors. GPEs, including hydrogels, organogels, and ionogels, are favored due to their tunable physicochemical and mechanical properties. However, commercialization is hindered by issues such as ionic conductivity, solvent evaporation, toxicity, and mechanical stability. The review highlights strategies to enhance GPE properties, such as using dynamic covalent bonds, flame retardant additives, and thermoresponsive materials. It also explores the design and applications of GPEs in batteries and supercapacitors, detailing the challenges and solutions in achieving high performance while maintaining flexibility and self-healing capabilities. Key advancements include the development of ionogels with high ionic conductivity, stretchability, and self-healing properties, as well as hydrogels with improved mechanical properties and antifreezing capabilities. The review emphasizes the ongoing efforts to find the best compromise between mechanical properties and electrochemical performance to advance the field of flexible energy storage systems.This review discusses the recent advancements in gel polymer electrolytes (GPEs) for flexible energy storage applications, focusing on batteries and supercapacitors. GPEs, including hydrogels, organogels, and ionogels, are favored due to their tunable physicochemical and mechanical properties. However, commercialization is hindered by issues such as ionic conductivity, solvent evaporation, toxicity, and mechanical stability. The review highlights strategies to enhance GPE properties, such as using dynamic covalent bonds, flame retardant additives, and thermoresponsive materials. It also explores the design and applications of GPEs in batteries and supercapacitors, detailing the challenges and solutions in achieving high performance while maintaining flexibility and self-healing capabilities. Key advancements include the development of ionogels with high ionic conductivity, stretchability, and self-healing properties, as well as hydrogels with improved mechanical properties and antifreezing capabilities. The review emphasizes the ongoing efforts to find the best compromise between mechanical properties and electrochemical performance to advance the field of flexible energy storage systems.