Organic memristive devices are of great interest nowadays due to their low costs, flexibility, and prospects of use in artificial neuromorphic systems. Polyaniline (PANI) is a conductive and electrochemically active polymer and a promising material for redox‐gated memristive devices. In this work, the electrochromic properties of PANI are utilized for spatially resolved mapping of electrochemical reactions in the active zone of a model PANI‐based device. The observed nonuniform propagation of the reaction front defines the difference in the kinetics of the device while switching from the low‐ to high‐resistance state and vice versa. This study both reveals the mechanism of resistive switching in redox‐gated memristive elements and offers a novel nondestructive method for monitoring the resistive state of PANI‐based memristive devices.