To optimize devices, elementary steps that store or transfer charge must be identified Organic electrochemical devices, which use conjugated polymers in contact with an electrolyte, have applications in bioelectronics, energy storage, electrocatalysis, and sensors ( 1 , 2 ). Their operation relies on the oxidation (electron loss) or reduction (electron gain) of the polymer, which are traditionally described as Faradaic processes that transfer charge ( 3 ). However, recent evidence from various devices based on poly(3,4-ethylenedioxythiophene) chemically doped with poly(styrene sulfonate) (PEDOT:PSS) is consistent with a purely capacitive process that stores charge ( 4 ). To clarify whether PEDOT:PSS is an exception or the rule and determine which processes are capacitive and which are Faradaic, solid-state physics methodology developed to understand the operation of organic light-emitting diodes (OLEDs) can be used ( 5 ). Such studies can pave the way for device optimization.