This review provides a comprehensive overview of the latest advancements in M4X3 MXenes, focusing on their properties and applications in energy storage devices, particularly supercapacitors (SCs). MXenes, a family of two-dimensional (2D) materials, exhibit unique properties such as excellent thermal stability, high conductivity, good hydrophilicity, and tunable surface chemistry. Among various MXene families, M4X3 MXenes have received less attention compared to M2X and M3X2, but recent studies have highlighted their exceptional electronic, magnetic, electrochemical, optical, and mechanical properties. The review discusses the synthesis methods, structural characteristics, and electrochemical performance of M4X3 MXenes, including Ta4C3, Nb4C3, V4C3, and Mo2Ti3C3. These materials show promising performance in SCs due to their large interlayer spacing, high specific surface areas, and efficient charge transport. The review also explores the potential of M4X3 MXenes in enhancing the performance of SCs through structural modifications and surface functionalization. Despite the challenges, the review suggests future directions for further research, including the exploration of double transition metal MXenes and the optimization of synthesis processes to tailor the properties of M4X3 MXenes for advanced energy storage applications.This review provides a comprehensive overview of the latest advancements in M4X3 MXenes, focusing on their properties and applications in energy storage devices, particularly supercapacitors (SCs). MXenes, a family of two-dimensional (2D) materials, exhibit unique properties such as excellent thermal stability, high conductivity, good hydrophilicity, and tunable surface chemistry. Among various MXene families, M4X3 MXenes have received less attention compared to M2X and M3X2, but recent studies have highlighted their exceptional electronic, magnetic, electrochemical, optical, and mechanical properties. The review discusses the synthesis methods, structural characteristics, and electrochemical performance of M4X3 MXenes, including Ta4C3, Nb4C3, V4C3, and Mo2Ti3C3. These materials show promising performance in SCs due to their large interlayer spacing, high specific surface areas, and efficient charge transport. The review also explores the potential of M4X3 MXenes in enhancing the performance of SCs through structural modifications and surface functionalization. Despite the challenges, the review suggests future directions for further research, including the exploration of double transition metal MXenes and the optimization of synthesis processes to tailor the properties of M4X3 MXenes for advanced energy storage applications.