This review article evaluates the performance of supercapacitors (SCs) by analyzing key parameters, including cell capacitance, operating voltage, equivalent series resistance (ESR), power density, energy density, and time constant. The study highlights the inconsistencies in evaluation methods and practices, which hinder effective communication of research findings and the commercialization of SC technologies. The authors aim to streamline the commonly used instruments, key performance metrics, calculation methods, and major affecting factors for SC performance evaluation. They emphasize the importance of distinguishing between device performance and material properties, as well as the rate dependency of SCs. The review discusses various evaluation methods, including cyclic voltammetry (CV), constant current charge/discharge (CCCD), and electrochemical impedance spectroscopy (EIS), and their applications in determining SC parameters. The study also addresses the impact of factors such as experimental setup, mass loading, electrode thickness, and electrode density on SC performance. The authors conclude that while CCCD tests are the most effective and accurate for measuring SC parameters, inconsistencies in test results due to different methods and setups remain a challenge. The review provides a comprehensive overview of SC performance evaluation, aiming to improve the reliability and comparability of results in the field.This review article evaluates the performance of supercapacitors (SCs) by analyzing key parameters, including cell capacitance, operating voltage, equivalent series resistance (ESR), power density, energy density, and time constant. The study highlights the inconsistencies in evaluation methods and practices, which hinder effective communication of research findings and the commercialization of SC technologies. The authors aim to streamline the commonly used instruments, key performance metrics, calculation methods, and major affecting factors for SC performance evaluation. They emphasize the importance of distinguishing between device performance and material properties, as well as the rate dependency of SCs. The review discusses various evaluation methods, including cyclic voltammetry (CV), constant current charge/discharge (CCCD), and electrochemical impedance spectroscopy (EIS), and their applications in determining SC parameters. The study also addresses the impact of factors such as experimental setup, mass loading, electrode thickness, and electrode density on SC performance. The authors conclude that while CCCD tests are the most effective and accurate for measuring SC parameters, inconsistencies in test results due to different methods and setups remain a challenge. The review provides a comprehensive overview of SC performance evaluation, aiming to improve the reliability and comparability of results in the field.