The paper provides a comprehensive review of microfluidic mixing techniques, focusing on both active and passive methods. Active mixers enhance mixing by applying external energy, such as acoustic, dielectrophoretic, electrokinetic, pressure perturbation, electrohydrodynamic, thermal, magneto-hydrodynamic, and electrokinetic instability forces. Passive mixers, on the other hand, rely on increasing the contact area and contact time between the samples through microchannel designs. The review highlights the advantages and disadvantages of each type of mixer, emphasizing their suitability for different applications. Active mixers are generally faster but require more complex fabrication processes, while passive mixers are simpler and more cost-effective. The paper also discusses the impact of microfluidic mixing on various fields, including biomedical diagnostics, drug development, and chemical industries, and concludes by summarizing the advancements and future directions in microfluidic mixing technology.The paper provides a comprehensive review of microfluidic mixing techniques, focusing on both active and passive methods. Active mixers enhance mixing by applying external energy, such as acoustic, dielectrophoretic, electrokinetic, pressure perturbation, electrohydrodynamic, thermal, magneto-hydrodynamic, and electrokinetic instability forces. Passive mixers, on the other hand, rely on increasing the contact area and contact time between the samples through microchannel designs. The review highlights the advantages and disadvantages of each type of mixer, emphasizing their suitability for different applications. Active mixers are generally faster but require more complex fabrication processes, while passive mixers are simpler and more cost-effective. The paper also discusses the impact of microfluidic mixing on various fields, including biomedical diagnostics, drug development, and chemical industries, and concludes by summarizing the advancements and future directions in microfluidic mixing technology.