Nanostructured carbons with a number of redox-active sites play a key role as active electrode materials for supercapacitors and rechargeable batteries, owing to their pseudocapacitive charge storage behaviors. Nevertheless, there is currently no method to characterize the level of contribution of pseudocapacitance in overall capacitance values, hindering technological and scientific advancement of pseudocapacitive electrode materials. In this study, we can observe the voltage-dependent pseudocapacitive behaviors of heteroatom-enriched nanoporous carbons, which can be detected through a simple comparison of electrochemically obtained results in both aqueous and organic electrolyte systems. It is also confirmed that the voltage-dependent pseudocapacitive behaviors are so fast and stable that the heteroatom-enriched nanoporous carbons based on the voltage-dependent pseudocapacitive behaviors can deliver high specific energy and power as cathodes when they are assembled with a proper counterpart anode.